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The existing research on CH4 displacement by N2 mainly focuses on the gas injection displacement mechanism and the factors affecting displacement efficiency. And most of them are theoretical analyses at the model level or multifactor analyses at the simulation test level, while there are few targeted physical simulation tests and quantitative analyses. Given the above problems, the experiment system was used to study the gas migration evolution law and time-varying characteristics of CH4 displacement by N2 in coal under different injection pressures. The experimental results show that the whole process of CH4 displacement by N2 can be divided into three stages: stage I (original equilibrium stage); stage II (dynamic balance stage); stage III (new equilibrium stage). The concentration of CH4 and N2 presents an opposite variation trend, and the variation rate of CH4 and N2 increased first and then decreased. The breakthrough time was 50 minutes, 45 minutes, 35 minutes, 25 minutes, and 20 minutes, respectively, under different injection pressures. The displacement efficiency increased with the injection pressures, while the replacement ratio decreased with the injection pressures. The maximum flow rate of CH4 was 0.085 mL/min, 0.110 mL/min, 0.130 mL/min, 0.222 mL/min, and 0.273 mL/min, respectively, under different injection pressures. The accumulated production of CH4 was 3.59 mL, 3.91 mL, 4.39 mL, 5.58 mL, and 5.94 mL, respectively, under different injection pressures. The effective injection pressure range was 1.6~2 MPa. This research can provide a reference for the theoretical research of N2-ECBM-related technology in low permeability reservoirs and the selection of injection pressure in the field technology implementation. [ABSTRACT FROM AUTHOR]

The surface wettability is important in the change in the relative permeability of gas and water. Due to the heterogeneous property of coal, it has a mixed wetting state, which makes it difficult to predict the change in permeability. To investigate the influence of different wettabilities on two-phase flow, a total of three different rank coal samples were collected and were treated with different chemicals. The alteration of the coal's wettability, characteristics of gas–water flow, and relative permeability of the coal after the chemical treatments were analyzed. The research conclusions suggest that (1) the coal samples treated with SiO2 and H2O2 increased the hydrophilicity of the coal surface, while the coal samples treated with DTAB increased the hydrophobicity of the coal surface. Compared to SiO2, both H2O2 and DTAB can form a uniform wetting surface. (2) The wettability alteration mechanism among the three different chemical reagents is different. (3) All the chemicals can change the gas–water interface. The water migrates more easily through the cleats after H2O2 treatment, while it is more difficult for the water to migrate through cleats after the DTAB treatment. (4) There are two types of flow states of gas and water on different wetting surfaces. A slug flow is formed on a hydrophilic surface, while an annular flow is formed on a hydrophobic surface. (5) The crossover point and the residual water saturation of the relative permeability curves were influenced by the surface wettability. [ABSTRACT FROM AUTHOR]

We propose the quaternary AlInGaN last quantum barrier (LQB) structure to improve the performance of deep-ultraviolet (DUV) laser diodes (LDs). Here, we investigate three LQB structures – Al0.63In0.03Ga0.34N LQB, Al0.65In0.03Ga0.32N LQ band, and Al0.68In0.03Ga0.29N LQB. We find that the Al0.68In0.03Ga0.29N LQB structure significantly reduces the electron leakage in the p-region, improves the carrier injection efficiency in the active region, and increases the stimulated radiation recombination rate of the DUV LDs. The simulation results indicate that the threshold current and threshold voltage decrease from 50.93 mA and 4.70 V for the Al0.63In0.03Ga0.34N LQB structure to 42.47 mA and 4.63 V for the Al0.68In0.03Ga0.29N LQB structure, respectively. At an injection current of 100 mA, the slope efficiency increases to 1.12 W/A. Compared with the conventional ternary AlGaN LQB structure, the quaternary AlInGaN LQB structure significantly improves the performance of the DUV LDs, which is crucial for the development of the DUV LDs. [ABSTRACT FROM AUTHOR]

There exists an extensive research interest in the performance improvement of AlGaN-based deep-ultraviolet (DUV) laser diodes (LDs). Herein, to reduce the carrier leakage problem of LDs, we propose a convex waveguide (WG) layer for improving the optoelectronic properties. Numerical analyses are carried out to compare the proposed convex WG layer with traditional and stepped WG layers. For LDs with seven different WG layers, parameters used for comparison are P – I and V – I characteristic curves, carrier concentrations, stimulated recombination rates, slope efficiencies, and electro-optical conversion efficiencies. We show that the application of the convex WG layer considerably enhances the carrier confinement ability of LDs and reduces carrier leakage, improving the performance of the LDs. The overall performance of LDs with only a convex lower WG (LWG) layer or a stepped LWG layer is stronger than that of LDs with only a convex upper WG (UWG) layer or a stepped UWG layer. [ABSTRACT FROM AUTHOR]

To improve the carrier confinement capability and optimize the performance of deep ultraviolet laser diodes (DUV-LDs), we propose the graded rectangular superlattice (GRSL) electron blocking layer (EBL) and the graded trapezoidal superlattice (GTSL) hole blocking layer (HBL) in this paper. Crosslight software is used to simulate and compare the DUV-LDs with rectangular superlattice (RSL) EBL and RSL HBL, GRSL EBL and GRSL HBL, and GRSL EBL and GTSL HBL. The simulation results indicate that GRSL EBL and GTSL HBL increase the carrier concentration in the quantum wells, reduce the electron leakage in the p-type region and the hole leakage in the n-type region, increase the radiation recombination rate, reduce the threshold voltage and threshold current, and increase the electro-optical conversion efficiency and output power of DUV-LDs more effectively. [ABSTRACT FROM AUTHOR]

The deep ultraviolet (DUV) micro-light emitting diode (μLED) has serious electron leakage and low hole injection efficiency. Meanwhile, with the decrease in the size of the LED chip, the plasma-assisted dry etching process will cause damage to the side wall of the mesa, which will form a carrier leakage channel and produce non-radiative recombination. All of these will reduce the photoelectric performance of μLED. To this end, this study introduces polarized bulk charges into the hole supply layer (p-HSL) and the electron supply layer (n-ESL) respectively (dual-polarized structure) of the DUV μLED at an emission wavelength of 279 nm to enhance the binding of carriers and increase the injection efficiency of carriers. This is because the polarization-induced bulk charge can shield the polarized sheet charge on the interface and reduce the polarization electric field. The reduced polarization electric field in p-HSL can increase the effective barrier height of the conduction band in the p-type region and reduce the effective barrier height of the valence band. The decrease in the polarized electric field of n-HSL can reduce the thermal velocity of electrons, thereby enhancing the electron injection efficiency, reducing the Shockley–Read–Hall (SRH) recombination, and increasing the effective barrier height of the valence band. The study results indicate that the electron concentration and hole concentration of a μLED with dual polarization were increased by 77.93% and 93.6%, respectively. The optical power and maximum external quantum efficiency of μLED reached 31.04 W/cm2 and 2.91% respectively, and the efficiency droop is only 2.06% at 120 A/cm2. These results provide a new approach to solving the problem of insufficient carrier injection and SRH recombination in high-performance DUV μLEDs. [ABSTRACT FROM AUTHOR]

The correlation between renewable energy technology innovation (RENTI) and carbon neutrality has been studied extensively. Meanwhile, an efficient digital financial system and a favorable innovation environment are essential to promote RENTI. This paper examines the effects of digital finance and the regional innovation environment on RENTI using panel data from 31 Chinese provinces spanning 2011 to 2020. The findings demonstrate that digital finance directly promotes RENTI. The marginal effect of digital finance is more significant for eastern regions and regions with developed finance. The threshold effect analysis shows that the positive impact of digital finance on RENTI reaches a higher level when government financial support and ICT development exceed a certain threshold. In addition, appropriate levels of human capital are conducive to the positive impact of digital finance. Finally, we find that digital finance promotes local RENTI and benefits RENTI in neighboring regions. Our findings offer insights for policymakers to guide digital finance to support RENTI and optimize the innovation environment. [ABSTRACT FROM AUTHOR]

Aluminum-rich p-AlGaN electron-blocking layers (p-EBL) usually block the hole injection in the AlGaN-based deep ultraviolet (DUV) light-emitting diode (LED). Meanwhile, the ionization energy of the magnesium receptors in the aluminum-rich p-AlGaN layer is considerably high, and the conductivity is low, leading to a reduction in the hole injection capability. Consequently, AlGaN-based DUV LEDs suffer from a low internal quantum efficiency (IQE). A structure of p-EBL and hole source layer (p-HSL) using AlN composition gradient AlGaN is proposed. The polarization bulk charges are introduced in both p-EBL and p-HSL (the p-type dual polarization) to shield the polarization-induced electric field and increase the hole energy. Although the single-polarized structure of p-EBL or p-HSL can also effectively enhance the performance of the device, calculation results indicate that the performance of the p-type dual-polarized structure can be doubled. This is because optimizing a single p-EBL or p-HSL can only introduce polarization bulk charge in the monolayer but not in all p-type regions. Therefore, in LEDs with shorter wavelengths, to maximize the hole energy, a dual-polarization structure should be adopted for the p-type region. Based on this, a maximum IQE of 55.65% and an efficiency droop of 4.84% are obtained at a wavelength of 237 nm. Findings of this study provide insights to solve the problem of low IQE in high-performance DUV LEDs. [ABSTRACT FROM AUTHOR]

Exploring the relationship between government subsidies, market competition, and the total factor productivity (TFP) of new energy enterprises will help countries optimize renewable energy support policies in the context of carbon neutrality constraints and energy demand growth. Based on the panel data of 145 listed new energy enterprises from 2007 to 2020, this paper investigates how government subsidies affect the TFP of new energy enterprises and the moderating effects of market competition. Our main findings are as follows: (1) Government subsidies positively affect the TFP of new energy enterprises. Heterogeneity analysis suggests that government subsidies have a larger effect on the TFP of non-SOEs, midstream and upstream enterprises, and smaller enterprises. (2) Industry market competition negatively moderates the effect of government subsidies on TFP, while enterprise competition power has a positive moderating effect. The marginal effect of government subsidies is significantly positive only when the industry market competition is below a certain threshold or the enterprise competitive power exceeds a certain threshold. (3) Government subsidies enhance the TFP by promoting invention and utility model innovation of new energy enterprises. In addition, market competition significantly moderates the relationship between government subsidies and utility model innovation, thereby moderating the marginal effect of government subsidies on TFP. The findings contribute to a better understanding of the relationship between government support, market competition, and new energy development. [ABSTRACT FROM AUTHOR]

Background: Optimum flowering time is a key agronomic trait in Brassica napus. To investigate the genetic architecture and genetic regulation of flowering time in this important crop, we conducted quantitative trait loci (QTL) analysis of flowering time in a recombinant inbred line (RIL) population, including lines with extreme differences in flowering time, in six environments, along with RNA-Seq analysis. Results: We detected 27 QTLs distributed on eight chromosomes among six environments, including one major QTL on chromosome C02 that explained 11–25% of the phenotypic variation and was stably detected in all six environments. RNA-Seq analysis revealed 105 flowering time-related differentially expressed genes (DEGs) that play roles in the circadian clock/photoperiod, autonomous pathway, and hormone and vernalization pathways. We focused on DEGs related to the regulation of flowering time, especially DEGs in QTL regions. Conclusions: We identified 45 flowering time-related genes in these QTL regions, eight of which are DEGs, including key flowering time genes PSEUDO RESPONSE REGULATOR 7 (PRR7) and FY (located in a major QTL region on C02). These findings provide insights into the genetic architecture of flowering time in B. napus. [ABSTRACT FROM AUTHOR]

To improve the carrier injection efficiency and optimize the performance of the AlGaN-based deep ultraviolet laser diodes (DUV-LDs), one-way step-shaped quantum barriers (OWS-QBs), a symmetrical step-shaped electron blocking layer (SS-EBL), and a symmetrical step-shaped hole blocking layer (SS-HBL) are proposed. Crosslight software is used to simulate the DUV-LDs with a traditional structure, with OWS-QBs, and with OWS-QBs, a SS-EBL, and a SS-HBL. The simulation results and physical mechanism analysis indicate that the SS-EBL, SS-HBL, and OWS-QBs contribute to the increased carrier concentration in the quantum wells, the reduced carrier leakage in the nonactive regions, the increased stimulated emission rate, the reduced threshold current and threshold voltage, and the enhanced output power and electro-optical conversion efficiency of DUV-LDs. [ABSTRACT FROM AUTHOR]

Inversion of atmospheric ducts is of great importance in the field of performance evaluation for radar and communication systems. Since the model parameters in machine learning play a crucial role in prediction performance, this paper develops a random forest (RF) model integrated with Bayesian optimization (BO) called BO-RF for atmospheric duct prediction, and the BO is adopted to determine appropriate model parameters during the training process. In addition, the K-fold cross-validation (CV) method is also incorporated into the model to obtain the best model partition and overcome the overfitting problem. To test the performance of the proposed model, the results obtained by the BO-RF are compared with other commonly used methods, such as classical RF, extreme gradient boosting (XGBoost) with/without BO, and K-nearest neighbor (KNN) with/without BO. Comparisons demonstrate that BO-RF has the best accuracy and anti-noise ability for the estimation of duct parameters. [ABSTRACT FROM AUTHOR]

In the social context of mitigating climate change and achieving carbon neutrality, the improvement of carbon emissions efficiency and the protection of biological carbon sequestration have emerged as hot topics recently due to their prospects in carbon dioxide emissions reductions. A large volume of studies has identified the spatial distribution characteristics and influencing factors of carbon emissions efficiency. The contributions of our study lied in constructing a system to measure net carbon sink efficiency. Secondly, this study discussed the carbon neutrality performance of Chinese cities from three different aspects of carbon dioxide emissions, carbon sequestration of vegetation and net carbon sink efficiency. Thirdly, this paper identified the influencing factors of net carbon sink efficiency, and examined the direct and indirect effect of different factors. For this purpose, we evaluated the net carbon sink efficiency of 285 cities in China from 2012 to 2017 using a slacks-based measure model, and explored its spatial distribution characteristics, then employed a spatial Durbin model to explore the influencing factors of net carbon sink efficiency. Our main findings indicate that the net carbon sink efficiency steadily increased during the study period, whereas their spatial characteristics were "high at both ends and low in the middle" from the south to the north. There is a significant spatial autocorrelation in the net carbon sink efficiency of Chinese cities. Several kinds of measures can be applied to promote net carbon sink efficiency, such as increasing the proportion of tertiary industry, promoting economic growth, attracting foreign direct investment, increasing road area, promoting technological progress and strengthening environmental regulation. However, the increase of urban population may decrease efficiency. Nevertheless, an obvious spatial spillover effect exists in the net carbon sink efficiency of Chinese cities. The results can provide policy recommendations for the government to formulate differentiated carbon neutralization policies. [Display omitted] • The carbon sequestration is considered to calculate net carbon sink efficiency (NCSE). • The NCSE is used to discuss the carbon neutral performance of Chinese cities. • Chinese NCSE steadily increased and showed significant spatial autocorrelation. • Spatial Durbin model was adopted to study the influencing factors of NCSE. [ABSTRACT FROM AUTHOR]

Green credit policy (GCP) is an important practical exploration to guide green economic development by financial means. Empirically, however, little is known about the relationship between GCP and industrial carbon emissions intensity (CEI). This study aims to investigate the impact of GCP on the CEI of heavily polluting industries (HPIs) by treating Green Credit Guidelines as a quasi-natural experiment. Using Chinese industry-level panel data and a difference-in-difference model, we find that after the implementation of GCP, the CEI of HPIs decreased by an average of 0.267 tons/104 yuan per year compared to non-HPIs. Resource allocation effect and green innovation effect are two channels through which GCP reduces CEI of HPIs. Moreover, the GCP has a greater effect on the CEI of HPIs with lower state-owned ratios, higher total factor productivity and higher capital dependence. These findings provide policy insights for promoting industrial carbon emissions reduction. • The green credit policy (GCP) reduces the carbon emissions intensity (CEI) of heavily polluting industries (HPIs). • The GCP reduces the CEI of HPIs through resource allocation effect and green innovation effect. • The GCP has a greater effect on HPIs with lower state-owned ratios, higher productivity and higher capital dependence. • The GCP has an asymmetric effect on average market share, energy intensity and green innovation. [ABSTRACT FROM AUTHOR]

A deep-ultraviolet (DUV) laser diode (LD) consisting of specifically designed cladding layers involving superlattice nitride alloy has been proposed. Simulation studies of different cladding layers were carried out using Crosslight software. It was found that the proposed structure effectively suppresses the leakage of the optical field from the active region and the optical confinement coefficient is 1.45 times higher than that of the conventional structure. The proposed structure has a significant increase in laser power with a low threshold current. Moreover, the introduction of novel cladding layer suppresses the electron and hole leakage from the multiple quantum well (MQW) region, which provides an attractive solution for increasing the stimulated recombination rate in the MQW region leading to the improvement in the performance of the DUV LD. [ABSTRACT FROM AUTHOR]

Nanoindentation has emerged as a pioneering technique for fabricating array structures at the nanoscale. This research incorporates molecular dynamics simulations to investigate the deformation mechanisms of materials influenced by structured indenters exhibiting diverse geometries. The primary objective of this study is to mitigate interference during the continuous indentation applied by the indenters, diminish the material's elastic recovery, and minimize the occurrence of defects. The simulation results unveil that plastic deformation of the workpiece induced by structured indenters manifests through the nucleation and slip of dislocations. The cylindrical indenter engenders the most pronounced residual indentation morphology, accompanied by substantial pile-up interference and an extensive range of dislocation expansion, surpassing that of other indenters. Conversely, pyramidal indenters exhibit minimal residual indentation morphology, albeit displaying considerable elastic recovery. A comprehensive evaluation that considers factors such as recovery after indentation, ease of processing, system stability, and material transfer against the indentation force is imperative for the determination of the ideally structured indenter. The meticulous analysis supports the efficacy of paraboloidal indenters possessing smaller taper angles in attaining consistent processing results, rendering them highly suitable for continuous indentation processing. The research content bears significant implications for advancing the application of structured indenters. [Display omitted] • The defect evolution mechanisms of the structured indentation processing were analyzed. • The plastic deformation mechanisms of structured indenters processing were analyzed. • The filling rates of characteristic gaps were presented and calculated for structured indenters. • The indentation recovery rate and stability of the structured indenter were calculated and analyzed. [ABSTRACT FROM AUTHOR]

Digital economy development (DED) empowers rural habitat (RH) improvement and promotes the construction of harmonious villages. Based on a panel data of 30 provinces in China from 2013 to 2019, this paper empirically tests the impact of DED on RH and its endogenous mechanism in multiple dimensions using panel fixed effects model and spatial Durbin model. The results show that DED significantly improves RH, which remains robust after a series of robustness tests and dealing with endogeneity issues. The mechanism analysis shows that DED helps to bring into play the rural resource allocation effect, the innovation and entrepreneurship effect, and the carbon emission reduction effect, and improves the RH through these three effects. Further study finds that the digital application divide and regional divide are the main barriers to digital technology enabling RH improvement, there is a spatial spillover effect of DED, which helps to promote the improvement of RH in neighboring areas. The results of the study can provide theoretical support and decision-making reference for the construction of digital villages and the balanced regional development of RH in China. • Indicator system of digital economy and rural habitat was constructed. • Digital economy development significantly boosts rural habitat. • Resource allocation, rural entrepreneurship, and carbon reduction are effective transmission mechanisms. • Digital application divide has a heterogeneity impact. • The spatial spillover effect of the digital economy is significant. [ABSTRACT FROM AUTHOR]

Rural revitalization is inseparable from the construction of human habitat, the coordinated development of rural culture and physical environment profoundly affects the quality of the habitat environment, and the improvement of the habitat environment requires a "soft and hard balance". Previous studies have focused more on the overall quality of rural habitat and neglected the coordination of habitat construction. The contribution of our study is the construction of an evaluation index system for the China Rural Habitat Coordinated Degree (CRHCD). The main research results show that the level of soft and hard environment of China's rural habitat is growing, but the construction of soft environment is a shortcoming. CRHCD leaps from nearly dysfunctional (0.440) to barely coordinated (0.538), and is in a transitional stage with stable spatial structure, showing the trend of "from point to line, from line to surface", and gradually developing from coastal to inland. Spatial convergence analysis shows that CRHCD converges fastest in the eastern region, while the northeastern region shows dispersion characteristics. Our results provide a theoretical basis and policy recommendations for the systematic coordination and regional balanced development of rural habitat in China. • The China Rural Habitat Coordinated Degree from the perspective of soft and hard environments were conceptualized. • Evaluation index system and quantitative methods for the China Rural Habitat Coordinated Degree were put forward. • The China Rural Habitat Coordinated Degree was measured and the spatio-temporal divergence pattern was explored. • Rural internal and external conditions can affect the spatial convergence of the China Rural Habitat Coordinated Degree. [ABSTRACT FROM AUTHOR]

Leaf size and shape play important roles in agronomic traits, such as yield, quality and stress responses. Wide variations in leaf morphological traits exist in cultivated varieties of many plant species. By now, the genetics of leaf shape and size have not been characterized in Brassica napus. In this study, a population of 172 recombinant inbred lines (RILs) was used for quantitative trait locus (QTL) analysis of leaf morphology traits. Furthermore, fresh young leaves of extreme lines with more leaf lobes (referred to as ‘A’) and extreme lines with fewer lobes (referred to as ‘B’) selected from the RIL population and leaves of dissected lines (referred to as ‘P’) were used for transcriptional analysis. A total of 31 QTLs for the leaf morphological traits tested in this study were identified on 12 chromosomes, explaining 5.32–39.34% of the phenotypic variation. There were 8, 6, 2, 5, 8, and 2 QTLs for PL (petiole length), PN (lobe number), LW (lamina width), LL (Lamina length), LL/LTL (the lamina size ratio) and LTL (leaf total length), respectively. In addition, 74, 1,166 and 1,272 differentially expressed genes (DEGs) were identified in ‘A vs B’, ‘A vs P’ and ‘B vs P’ comparisons, respectively. The Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were used to predict the functions of these DEGs. Gene regulators of leaf shape and size, such as ASYMMETRIC LEAVES 2, gibberellin 20-oxidase 3, genes encoding gibberellin-regulated family protein, genes encoding growth-regulating factor and KNOTTED1-like homeobox were also detected in DEGs. After integrating the QTL mapping and RNA sequencing data, 33 genes, including a gene encoding auxin-responsive GH3 family protein and a gene encoding sphere organelles protein-related gene, were selected as candidates that may control leaf shape. Our findings should be valuable for studies of the genetic control of leaf morphological trait regulation in B. napus. [ABSTRACT FROM AUTHOR]

The hormone auxin is involved in many biological processes throughout a plant's lifecycle. However, genes in the GH3 (Gretchen Hagen3) family, one of the three major auxin-responsive gene families, have not yet been identified in oilseed rape (Brassica napus). In this study, we identified 63 BnaGH3 genes in oilseed rape using homology searches. We analyzed the chromosome locations, gene structures, and phylogenetic relationships of the BnaGH3 genes, as well as the cis-elements in their promoters. Most BnaGH3 genes are located on chromosomes A03, A09, C02, C03, and C09, each with 4–7 members. In addition, we analyzed the expression patterns of BnaGH3 genes in seven tissues by transcriptome sequencing and quantitative RT-PCR analysis of plants under exogenous IAA treatment. The BnaGH3 genes showed different expression patterns in various tissues. BnaA.GH3.2-1 and BnaC.GH3.2-1 were expressed in the seed and seed coat during development and in response to IAA treatment. These results shed light on the possible roles of the GH3 gene family in oilseed rape. [ABSTRACT FROM AUTHOR]

MicroRNAs (miRNAs) have important roles in regulating stress-response genes in plants. However, identification of miRNAs and the corresponding target genes that are induced in response to cadmium (Cd) stress in Brassica napus remains limited. In the current study, we sequenced three small-RNA libraries from B. napus after 0 days, 1 days, and 3 days of Cd treatment. In total, 44 known miRNAs (belonging to 27 families) and 103 novel miRNAs were identified. A comprehensive analysis of miRNA expression profiles found 39 differentially expressed miRNAs between control and Cd-treated plants; 13 differentially expressed miRNAs were confirmed by qRT-PCR. Characterization of the corresponding target genes indicated functions in processes including transcription factor regulation, biotic stress response, ion homeostasis, and secondary metabolism. Furthermore, we propose a hypothetical model of the Cd-response mechanism in B. napus. Combined with qRT-PCR confirmation, our data suggested that miRNAs were involved in the regulations of TFs, biotic stress defense, ion homeostasis and secondary metabolism synthesis to respond Cd stress in B. napus. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polycrystalline Au nanowire formation mechanism under tool geometry is studied. • Large rake angles and small tool radii mean smaller nanowire thickness deviations. • Nanowires formation mechanism changes with varying tool morphology. • Microstructure evolution is sensitive to changing of tool geometry. Au nanowires have been promoted in flexible electronics, micro-nano bioelectrodes, and micro-electrochemical detection benefit from their inherent size effect, unique chemical stability, and biocompatibility. Nanoskiving methodology has been confirmed as a feasible approach to preparing multidimensional nanostructures simply and efficiently utilizing ultramicrotome. However, the morphology, dimension, and microstructure of the nanowires will be altered by the tool geometry under extrusion and shearing during the nanoskiving process. Herein, a molecular dynamics simulation and experiments of cutting polycrystalline Au utilizing nanoskiving were performed, and the nanowire formation behavior caused by the variation of the tool geometry was analyzed. Smaller rake angle and larger tool cutting edge radius favor thicker chip thickness, larger high-stress areas, increased machining forces, as well as a shift in cutting formation mechanism from shear to extrusion shear. The reduction in the clearance angle only increases the high-stress areas and machining forces. The stress state and dislocation density within the chip and plastic deformation zone were closely related to the tool topography. The conclusions provide a thorough technical analysis of the mechanism of polycrystalline Au nanowire formation as well as theoretical guidance for the design and selection of tools for nanoskiving processes. [ABSTRACT FROM AUTHOR]

The article discusses the research study done into the impact of coal fines in the development of coalbed methane (or CBM) in the Ordos Basin in China. Topics include the methods used to collect samples of coal fines from the CBM wells in this coal mining region and the results of the concentration of coal fines in each block.

• A two-step solvothermal route was used to prepare Zn 2 GeO 4 /MIL-125(Ti) composite. • The Zn 2 GeO 4 /MIL-125(Ti) catalyst exhibits excellent RhB 6G degradation performance. • The Zn 2 GeO 4 /MIL-125(Ti) photocatalyst also shows high stability and reusability. Zn 2 GeO 4 nanosheets/MIL-125(Ti) composites were successfully prepared via a facile two-step solvothermal route, and the phase structures were studied in detail. The as-obtained Zn 2 GeO 4 nanosheets/MIL-125(Ti) composites exhibited remarkable photocatalytic activity and excellent cycle stability for the degradation of RhB 6G dye molecules under a 300 W Xenon lamp light emitting UV and visible radiation over 300−700 nm. It was found that 100 mL of 10 mg L−1 RhB 6G can be completely degraded over 50 mg of Zn 2 GeO 4 nanosheets/MIL-125(Ti) photocatalyst within 90 min, and the degradation efficiency keep invariable after 4 cycles. MIL-125(Ti) endows the photocatalysts enhanced UV–vis light adsorption capability, while the Zn 2 GeO 4 nanosheet with relatively high surface area can effectively improve the charge transfer process of generated holes and pairs. Finally, the potential photocatalytic mechanism of photocatalysis of RhB 6G involved in the photoactive electrons and holes transfer was further discussed. [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is an effective way to improve the productivity of coalbed methane (CBM). But fines intrusion into fracturing proppant can result serious permeability change and gas productivity reduction. The effects of fines particle size and the inorganic mineral content of fines on fines migration and permeability changes in the proppant were investigated by physical simulation and experiments on coal and mudstone samples from the Hancheng block in the Eastern Ordos Basin. Based on analyzing the characteristics of output fines mass, size distribution, micro-morphology and mineralogy, the regularities of fines migration and the permeability affected by fines particle size and inorganic mineral content of fines were revealed. The results show that the output fines mass increases while the decreasing of the particle size of the injected fines and the inorganic mineral content of injected fines. The particle sizes of fines output get smaller with the increase of the flow velocity and the inorganic mineral content. The permeable capability of the proppant channel is influenced by particle size and inorganic mineral content as follows: (1) Proppant channels with fines of 63–125 μm in particle size show lower permeability during water injection than the other two groups of <63 μm and 125–200 μm (2) For coal-mudstone fines, the higher inorganic mineral content of the fines is, the lower permeability of the proppant channels is. This study identifies the effect patterns of fines particle sizes and inorganic mineral contents of the fines on fines migration in the proppant, and suggests improvement measures to generate less fines and improve fines migration capacity. • Fines mass and micro-morphology characteristics of fines output is analyzed. • Permeability is affected by the fines diameter and the inorganic mineral content. • The regularities of fines migration in the proppant have been concluded. [ABSTRACT FROM AUTHOR]

Glutathione transferases (GSTs) are multifunctional enzymes that play important roles in plant development and responses to biotic and abiotic stress. However, a systematic analysis of GST family members in Brassica napus has not yet been reported. In this study, we identified 179 full-length GST genes in B. napus, 44.2% of which are clustered on various chromosomes. In addition, we identified 141 duplicated GST gene pairs in B. napus. Molecular evolutionary analysis showed that speciation and whole-genome triplication played important roles in the divergence of the B. napus GST duplicated genes. Transcriptome analysis of 21 tissues at different developmental stages showed that 47.6% of duplicated GST gene pairs have divergent expression patterns, perhaps due to structural divergence. We constructed a GST gene coexpression network with genes encoding various transcription factors (NAC, MYB, WRKY and bZIP) and identified six modules, including genes expressed during late seed development (after 40 days; BnGSTU19, BnGSTU20 and BnGSTZ1) and in the seed coat (BnGSTF6 and BnGSTF12), stamen and anther (BnGSTF8), root and stem (BnGSTU21), leaves and funiculus, as well as during the late stage of pericarp development (after 40 days; BnGSTU12 and BnGSTF2) and in the radicle during seed germination (BnGSTF14, BnGSTU1, BnGSTU28, and BnGSTZ1). These findings lay the foundation for elucidating the roles of GSTs in B. napus. [ABSTRACT FROM AUTHOR]