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Abstract The existing hypervalent I(III) reagents bearing ONO2 group are limited in types and their applications primarily focused on the nitrooxylation reactions featuring a fully-exo fashion. Herein, a benziodazole-type O2NO-I(III) compound was prepared and its reaction with β-monosubstituted enamines in the presence of CuI could trigger a radical nitration/cyclization/dehydration cascade to provide a series of less explored but biologically interesting furazan heterocycles. Mechanistically, the benziodazole-type O2NO-I(III) compound acts as a nitrating reagent and incorporates its NO moiety into the final furazan product in a fully-endo model, a process of which was proposed to involve nitration, cyclization and dehydration.

A series of 4-thio/seleno-cyanated pyrazoles was conveniently synthesized from 4-unsubstituted pyrazoles using NH4SCN/KSeCN as thio/selenocyanogen sources and PhICl2 as the hypervalent iodine oxidant. This metal-free approach was postulated to involve the in situ generation of reactive thio/selenocyanogen chloride (Cl–SCN/SeCN) from the reaction of PhICl2 and NH4SCN/KSeCN, followed by an electrophilic thio/selenocyanation of the pyrazole skeleton.

Aconitum carmichaelii Debx., a traditional herb known for its potent bioactivities, has been widely used in Traditional Chinese Medicine, particularly in the forms of Chuanwu and Fuzi. Despite the therapeutic benefits of this plant, concerns have been raised regarding its neuropharmacological actions and potential neurotoxicity. This paper provides an in-depth analysis of the neuropharmacological effects, neurotoxicological mechanisms, and toxicity biomarkers of Aconitum roots. The neuropharmacological properties are linked to alterations in neurotransmitter synthesis and ion transport modulation, while the neurotoxic effects are primarily attributed to oxidative stress responses and the induction of mitochondrial apoptosis pathways. Through metabolomic profiling, we have identified several metabolic pathways affected by Aconitum roots, with a significant impact on tryptophan metabolism, which in turn influences cardiovascular and nervous system functions, liver detoxification, and energy metabolism. Furthermore, we discuss the modulation of ion channel protein activity, which is evidenced by recent studies, suggesting a critical role in the neurotoxic effects of Aconitum. An early detection strategy for toxicity biomarkers using metabonomics is proposed, emphasizing its crucial role in enhancing the diagnosis and treatment of Aconitum poisoning. It is recommended that regular monitoring of individuals at risk of Aconitum toxicity, including habitual consumers of TCM and accidental ingestion of the plant, be conducted in order to prevent toxic outcomes. This review emphasizes the importance of understanding the dual nature of Aconitum as both a therapeutic agent and a potential neurotoxin, aiming to optimize its clinical use and ensure patient safety.

In order to study the collision of sea ice on bridge piers of a sea-crossing bridge, this study establishes a finite element model of the impact of sea ice on bridge piers in aqueous media based on explicit dynamics analysis software and programming software using the arbitrary Lagrangian Eulerian (ALE) method. The results show that, when the sea-ice spacing is larger than the sea-ice edge length, the increase in sea-ice spacing leads to a decrease in the collision force and a significant increase in the probability of climbing and overturning. The increase in sea-ice mass significantly increases the impact force on the bridge abutment, and the peak value increases linearly with the increase in mass, and the sea-ice climbing and overturning phenomena are obvious. Different shapes of sea ice are obtained by cutting the sea-ice field with the two-dimensional Voronoi method, and the maximum impact force increases significantly with the increase in the average area. Irregularly shaped sea ice leads to a larger impact force and triggers the accumulation climbing phenomenon, which is verified by experiments, and the experimental values are in good agreement with the simulated values. In conclusion, this study reveals the significant effects of the spacing, mass, and shape of sea ice on the impact force of bridge piers, which provides an important reference for the design of bridge structures.

BackgroundThe agreement on the identification of sarcopenic obesity remains elusive, and its association with hyperuricemia remains unestablished. This study sought to evaluate the agreement of low lean mass (LLM) with obesity and its correlation with hyperuricemia.MethodsA total of 25,252 study participants, comprising 4,597 individuals with hyperuricemia, were obtained from the National Health and Nutrition Examination Survey spanning the years 1999–2006 and 2011–2018. LLM with obesity was characterized by the coexistence of LLM, determined by the ratio of appendicular lean mass to body mass index (BMI), and three categories of obesity including BMI, body fat percentage (BF%), and waist circumference (WC). We employed Cohen’s kappa to evaluate the agreement among the different diagnostic criteria and implemented survey multiple logistic regression and stratified analyses to explicate the connection between LLM with obesity and the risk of hyperuricemia.ResultsWhen defining obesity using BF%, BMI, and WC, the prevalence of LLM with obesity varied from 6.6 to 10.1%, with moderate-to-strong agreement. In the fully adjusted model, individuals with LLM or any of the three types of obesity exhibited notably elevated odds of developing hyperuricemia. Likewise, participants with LLM and obesity had 2.70 (LLM + BMI), 2.44 (LLM + BF%), and 3.12 (LLM + WC) times the risk of hyperuricemia, respectively, compared with healthy individuals. The association between LLM with obesity and hyperuricemia remained stable and significant across different age and sex subgroups.ConclusionWhen employing the three definitions of obesity, the incidence of LLM with obesity was not high, and the diagnostic agreement was relatively good. The participants with LLM and obesity exhibited an increased risk of hyperuricemia.

In this paper, we work on the discrete modified Leslie type predator-prey model with Holling type II functional response. The existence and local stability of the fixed points of this system are studied. According to bifurcation theory and normal forms, we investigate the codimension 1 and 2 bifurcations of positive fixed points, including the fold, 1:1 strong resonance, fold-flip and 1:2 strong resonance bifurcations. In particular, the discussion of discrete codimension 2 bifurcation is rare and difficult. Our work can be seen as an attempt to complement existing research on this topic. In addition, numerical analysis is used to demonstrate the correctness of the theoretical results. Our analysis of this discrete system revealed quite different dynamical behaviors than the continuous one.

The influence of Cr addition on the microstructure and tensile properties of Fe-25Mn-10Al-1.2C lightweight steel was investigated. The characteristics of the microstructures and deformation behavior were carried out through X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron backscatter diffraction (EBSD), and room temperature tensile testing. Fe-20Mn-12Al-1.5C steel without Cr exhibited a fully austenitic single phase. With the addition of Cr, the volume fraction of ferrite continuously increased. When the content of Cr exceeded 5 wt%, the precipitation of Cr7C3 carbides was observed. In the steel with 5 wt% Cr, the quantity of κ carbides remarkably decreased, indicating that the addition of 5 wt% Cr significantly inhibited the nucleation of κ-carbides. As the Cr content increases from 0 wt% to 5 wt%, the austenite grain sizes were 8.8 μm and 2.5 μm, respectively, demonstrating that Cr alloying is an effective method of grain refinement. Tensile strength increased slightly while elongation decreased with increasing Cr content. As the Cr content exceeded 5 wt%, the yield strength increased but the elongation drastically decreased. The steel with 2.5 wt% Cr achieved a synergistic improvement in strength and ductility, exhibiting the best tensile performance.

Abstract Angiosperms are one of the most diverse and abundant plant groups that are widely distributed on Earth, from tropical to temperate and polar zones. The wide distribution of angiosperms may be attributed to the evolution of sophisticated mechanisms of environmental adaptability, including cold tolerance. Since the development of high-throughput sequencing, transcriptome has been widely utilized to gain insights into the molecular mechanisms of plants in response to cold stress. However, previous studies generally focused on single or two species, and comparative transcriptome analyses for multispecies responding to cold stress were limited. In this study, we selected 11 representative angiosperm species, performed phylotranscriptome experiments at four time points before and after cold stress, and presented a profile of cold-induced transcriptome changes in angiosperms. Our multispecies cold-responsive RNA-seq datasets provide valuable references for exploring conserved and evolutionary mechanisms of angiosperms in adaptation to cold stress.

Abstract As an ambident nucleophile, controlling the reaction selectivities of nitrogen and oxygen atoms in amide moiety is a challenging issue in organic synthesis. Herein, we present a chemodivergent cycloisomerization approach to construct isoquinolinone and iminoisocoumarin skeletons from o-alkenylbenzamide derivatives. The chemo-controllable strategy employed an exclusive 1,2-aryl migration/elimination cascade, enabled by different hypervalent iodine species generated in situ from the reaction of iodosobenzene (PhIO) with MeOH or 2,4,6-tris-isopropylbenzene sulfonic acid. DFT studies revealed that the nitrogen and oxygen atoms of the intermediates in the two reaction systems have different nucleophilicities and thus produce the selectivity of N or O-attack modes.

Globally, the power sector must undergo a profound transition to achieve the decarbonization development targets. Various roadmaps are implemented, but only from a macro perspective, lacking the consideration of the electricity market rules. In this paper, we develop and present a market-driven generation and transmission expansion planning (MGTEP) model considering the effectiveness of the electricity market. Specifically, generation and transmission companies incorporate hourly market trading and annual capacity investment into strategic decisions to maximize their profits, with the supply function equilibrium model to analyze bidding behaviors. An equivalent quadratic programming formulation is deployed to solve the trilevel MGTEP model. Meanwhile, the MGTEP model is coupled with decarbonization policies to support the state and federal government in assessing energy transition strategies. We implement the MGTEP model with carbon emission allowance and carbon tax policies for the southern China electricity market to achieve carbon peaking by 2030. Carbon emission allowance adopts an intensity-based cap based on generation companies' historical output. The case study results show that 50 % carbon emission allowance or 400 CNY/t carbon tax is required but with several drawbacks, including unsatisfactory decarbonization effect, excessive economic sacrifice, etc. Finally, the case study is extended to dual-track policies with different combinations of policies. An optimal combination is 70 % carbon emission allowance and 160 CNY/t carbon tax. In this case, the power sector's carbon dioxide emissions and electricity prices in the southern China electricity market would increase to 554.6 Mt and 864.34 CNY/MWh in 2030, respectively, along with a carbon price of 850 CNY/t.

Active systems made of self-propelled units are widespread in nature, and Active Brownian particles (ABPs) are one of the simplest such system The authors theoretically and numerically investigate the collective assembly of ABPs finding a new re-entrant phase that enables motility-induced phase separation, which is dependent solely on activity.

In this work, a new amensalism system with the nonlinear Michaelis-Menten type harvesting for the second species is studied. Firstly, we clarify topological types for all possible equilibria of the system. Then, the behaviors near infinity and the existence of closed orbits as well as saddle connections of the system are discussed via bifurcation analysis, and the global phase portraits of the model are also illustrated. Finally, for the sake of comparison, we further offer a new complete global dynamics of the model without harvesting. Numerical simulations show that the system with harvesting has far richer dynamics, like preserving the extinction of the first species or approaching the steady-state more slowly. Our research will provide useful information which may help us have a better understanding to the dynamic complexity of amensalism systems with harvesting effects.

In this work, we propose and investigate a new predator-prey model with strong Allee effect in prey and Holling type Ⅱ functional response in predator. By performing a comprehensive dynamical analysis, we first derive the existence and stability of all the possible equilibria of the system and the system undergoes two transcritical bifurcations and one Hopf-bifurcation. Next, we have calculated the first Lyapunov coefficient and find the Hopf-bifurcation in this model is supercritical and a stable limit cycle is born. Then, by comparing the properties of the system with and without Allee effect, we show that the strong Allee effect is of great importance to the dynamics. It can drive the system to instability. Specifically, Allee effect can increase the extinction risk of populations and has the ability to switch the system's stability to limit cycle oscillation from stable node. Moreover, numerical simulations are presented to prove the validity of our findings.

3-Thiocyanated chromones was conveniently synthesized from alkynyl aryl ketones using commercially available, inexpensive trichloroisocyanuric acid (TCCA) as oxidant and NH4SCN as thiocyanato (SCN) source. This metal-free approach is postulated to first in situ generate thiocyanogen chloride (Cl-SCN) from the reaction of TCCA and NH4SCN, followed by a rare efficient electrophilic thiocyano oxyfunctionalization of alkynes enabled by the reactive electrophilic species generated thereof.

In this study, the effects of different bottom friction coefficient (BFC) parameterization schemes on the modelling of four principal tidal constituents (M2, S2, K1, O1 tides) in the macrotidal East China Seas were investigated by using a high-resolution model based on FVCOM (Finite Volume Community Ocean Model). The applied BFC schemes include: the empirical constant (EC-BFC), sediment-dependent form (SD-BFC), and spatial varying BFC obtained from adjoint data assimilation (SV-BFC). The comparisons between the simulated results and the observations from satellite altimeters and tidal gauge stations indicated that the SV-BFC scheme is superior to others. The locations of amphidromic points calculated with EC-BFC and SD-BFC were in the northwest of those from SV-BFC. The variations in tidal dynamics between different BFC schemes were closely related to the spatial distributions of BFCs, especially in high-valued BFC areas, e.g., the West Korea Bay, the South Yellow Sea, and the eastern coasts of Jiangsu, Zhejiang and Fujian provinces. The tidal energy flux transporting into Bohai and Yellow Seas increased under the SV-BFC scheme, while smaller tidal energy flux transporting from the Korea Strait was generated by SV-BFC as compared to those from EC-BFC and SD-BFC. The high-valued BFC areas in the SV-BFC scheme dissipated larger amounts of tidal energy, and the average values of Simpson-Hunter numbers were lower than those with the other two schemes. However, the values of Simpson-Hunter numbers increased in the West Korea Bay and Jianghua Bay with high-valued BFCs because of the decreasing current velocity under the headland-shaped topography.

Dioscin (DS) is a natural compound with inhibitory effects on multiple cancer types and we explored the mechanism driving the antagonizing effect of DS on osteosarcoma (OS). OS cell lines were treated with DS and microRNAs (miRs) responding to DS treatment were determined. Effects of DS on viability, apoptosis, metastasis, and miR-16-5p/HuR/Pim1 pathway activity were assessed. MiR-16-5p was inhibited before DS treatment to confirm its central role in anti-OS effects of DS. The conclusion derived from in vitro assays was verified with a mouse model. DS suppressed viability, invasion and migration, while induced apoptosis in OS cells. Moreover, the compound also induced the expression of miR-16-5p, contributing to the inhibition of HuR/Pim1 pathway. The inhibited expression of miR-16-5p counteracted the anti-OS function of DS, which was also validated in mice. Anti-OS effects of DS depended on the induction of miR-16-5p, making the compound a promising adjuvant agent for treating OS.

Small yellow croaker (Larimichthys polyactis), a benthic fish species widely distributed in the Northwest Pacific Ocean, plays an important role in the fishery catch of coastal countries. A large amount of dead small yellow croaker floated on the sea surface near 30.2°N, 125.3°E in the East China Sea on 19 February 2017, and more than 9,000 kilograms were caught by fishermen, which had never been recorded before. This study aims to investigate the dynamic causes of this sudden death event based on available in-situ, satellite and modelling data. The event occurred near the overwintering ground of small yellow croaker, where a majority of these fish assembled in winter. There were persistent ocean fronts at target site with average intensity of 0.05°C/km at sea surface and bottom in February 2017, which was the strongest in the past 5 years from 2015 to 2019. The fronts provided nutrients and food to fish, and the intense gradients prevented fish from crossing, thus forming “water barriers” to restrict the horizontal movement of fish. Due to enhanced convection, the water was well-mixed, enabling the demersal croaker to float to sea surface. The sea temperature was particularly warm in winter 2017, but then experienced a significant drop by more than 4.5°C in 40 days according to satellite and modelling datasets due to the northerly wind and the southeastward movement of cold eddy. The drop of temperature led to ‘cold shock’ of fish, affecting their physiological regulation and survival. Under the combined influence of these factors, a large number of small yellow croaker died and aggregated near the target site. This paper has a great reference value for further study on the living habits of small yellow croaker and their responses to marine dynamic changes.

The application of PhICl2/NH4SCN and PhICl2/KSeCN reagent systems to the synthesis of the biologically active S/SeCN-containing isocoumarins via a process involving thio/selenocyanation, enabled by thio/selenocyanogen chloride generated in situ, followed with an intramolecular lactonization was realized. Gram-scale synthesis, further derivatization to access C4 thio/selenocyanated Xyridin A and anti-tumor activities of the obtained products highlight the potential use of this method.

Abstract In this work, we propose and study a new amensalism system with Allee effect on the first species. First, we investigate the existence and stability of all possible coexistence equilibrium points and boundary equilibrium points of this system. Then, applying the Sotomayor theorem, we prove that there exists a saddle-node bifurcation under some suitable parameter conditions. Finally, we provide a specific example with corresponding numerical simulations to further demonstrate our theoretical results.

Abstract Cutting roof and release pressure technology has changed the pressure transmission mode of the roof and the caving characteristics of roof rock, which in turn has changed the permeability evolution of the gob. To obtain the permeability characteristics of the gob for the roof cutting and pressure releasing mining method, a mathematical model for the gob voidage and permeability was established by analyzing the overlying strata movement law and the lateral stress variation in the gob. The airflow migration law of haulage roadway 12 201 in Halagou coal mine was studied using Fluent software and an established mathematical model. The main conclusions obtained are as follows: The overburden pressure and lateral stress in the gob gradually increase with the advancement of the working face; along the direction of the retaining roadway, there are two roadway windflows entering the critical zones (the 22‐100 m and 390‐398 m sections). The inflow at these two sections accounted for 59% of the total air inflow, of which the most critical is the 28‐53 m section, which accounts for 43% of the total air inflow in the two severe air leakage sections. The findings of this work provide a theoretical basis for the implementation of antileakage technology in the gob under the roof cutting and pressure releasing mining method and help reduce the risk of spontaneous combustion in the gob.

Abstract Background The increasing number of organic and inorganic structures promotes the development of the “Big Data” in chemistry and material science, and raises the need for cross-platform and web-based methods to search, view and edit structures. Many web-based three-dimensional (3D) structure tools have been developed for displaying existing models, building new models, and preparing initial input files for external calculations. But few of these tools can deal with crystal structures. Results We developed a user-friendly and versatile program based on standard web techniques, such as Hyper Text Markup Language 5 (HTML5), Cascade Style Sheet (CSS) and JavaScript. Both non-periodic organic molecule and crystal structure can be visualized, built and edited interactively. The atom, bond, angle and dihedral in a molecule can be viewed and modified using sample mouse operations. A wide range of cheminformatics algorithms for crystal structure are provided, including cleaving surfaces, establishing vacuum layers, and building supercells. Four displayed styles, namely “Primitive cell”, “Original”, “In-cell” and “Packing” can be used to visualize a unit cell. Additionally, the initial input files for Vienna Ab-initio Simulation Package (VASP) and Gaussian can be obtained by interacting with dialog boxes in 3DStructGen. Conclusions 3DStructGen is a highly platform-independent program. It can provide web service independently or can be integrated into other web platforms. Other than local desktop software, it does not require any additional effort to install the system but a web browser supporting HTML5. 3DStructGen may play a valuable role in online chemistry education and pre-processing of quantum calculations. The program has been released under MIT open-source license and is available on: https://matgen.nscc-gz.cn/Tools.html.

The construction of the biologically interesting chromone skeleton was realized by PhIO-mediated dehydrogenation of chromanones under mild conditions. Interestingly, this method also found application in the synthesis of the naturally occurring frutinone A.

Abstract Performance of structure-based molecular docking largely depends on the accuracy of scoring functions. One important type of scoring functions are knowledge-based potentials derived from known three-dimensional structures of proteins and/or protein–ligand complex structures. This study seeks to improve a knowledge-based protein–ligand potential based on a distance-scale finite ideal-gas reference (DFIRE) state (DLIGAND) by expanding the representation of protein atoms from 13 mol2 atom types to 167 residue-specific atom types, and employing a recently updated dataset containing 12,450 monomer protein chains for training. We found that the updated version DLIGAND2 has a consistent improvement over DLIGAND in predicting binding affinities for either native complex structures or docking-generated poses. More importantly, DLIGAND2 has a 52% increase over DLIGAND in enrichment factors in top 1% predictions based on the DUD-E decoy set, and consistently improves over Autodock Vina and other statistical energy functions in all three benchmark tests. We further found that DLIGAND2 outperforms empirical and machine-learning methods compared for virtual screening on new targets that are not homologous to the DUD-E training set. Given the best performance as a parameter-free statistical potential and among the best in all performance measures, DLIGAND2 should be useful for re-assessing the poses generated by docking software, or acting as one term in other scoring functions. The program is available at https://github.com/sysu-yanglab/DLIGAND2.

Abstract Biogenic compounds are important materials for drug discovery and chemical biology. In this work, we report a quasi-biogenic molecule generator (QBMG) to compose virtual quasi-biogenic compound libraries by means of gated recurrent unit recurrent neural networks. The library includes stereo-chemical properties, which are crucial features of natural products. QMBG can reproduce the property distribution of the underlying training set, while being able to generate realistic, novel molecules outside of the training set. Furthermore, these compounds are associated with known bioactivities. A focused compound library based on a given chemotype/scaffold can also be generated by this approach combining transfer learning technology. This approach can be used to generate virtual compound libraries for pharmaceutical lead identification and optimization.

The prediction and development of three gases, mainly coalbed methane, shale gas, and tight sandstone gas, in the Huainan coal measures of China, has been the focus of local coal mines. However, due to the overlapping and coexisting characteristics of the three gas reservoirs in Huainan coal measure strata, it is challenging to develop the three gas. The coal mine has been creating a single pool for a long time, resulting in the severe waste of other gas resources in developing the gas-bearing resources in the coal measure strata. The gas-containing reservoir is predicted based on geological, seismic, and logging in Huainan Mining. In addition, determining the excellent area for reference for the development of three gas resources. First, using logging data, mathematical–statistical methods are used to analyze the physical parameters of gas-bearing reservoirs in multi-layered stacked coal seams. Then, based on the theory of prestack seismic inversion, parameters, such as the impedance of P-wave, the ratio of P-wave velocity and S-wave, Lamé constant, Young’s modulus, and Poisson’s ratio and lithological distribution, are obtained for the whole area. The gas-bearing information of the reservoir is received by the statistics and equation of the parameter intersection diagram and is closely related to exploration and development. Finally, the paper synthetically predicts the most favorable area of the gas-bearing reservoir in the study area. The prediction results are compared with the actual results of coalbed methane content in the existing extraction wells, proving that the method is feasible and can provide the basis for the deployment and development of the well location.

The determination of quantitative relationship between soil dielectric constant and water content is an important basis for measuring soil water content based on ground penetrating radar (GPR) technology. The calculation of soil volumetric water content using GPR technology is usually based on the classic Topp formula. However, there are large errors between measured values and calculated values when using the formula, and it cannot be flexibly applied to different media. To solve these problems, first, a combination of GPR and shallow drilling is used to calibrate the wave velocity to obtain an accurate dielectric constant. Then, combined with experimental moisture content, the intelligent group algorithm is applied to accurately build mathematical models of the relative dielectric constant and volumetric water content, and the Topp formula is revised for sand and clay media. Compared with the classic Topp formula, the average error rate of sand is decreased by nearly 15.8%, the average error rate of clay is decreased by 31.75%. The calculation accuracy of the formula has been greatly improved. It proves that the revised model is accurate, and at the same time, it proves the rationality of the method of using GPR wave velocity calibration method to accurately calculate the volumetric water content.

Among the various geological disasters that threaten the safe operation of long-distance oil and gas pipelines, water-damage disasters are numerous and widely developed. Especially the pipelines crossing river channels or gullies are vulnerable to scouring hazards from storms and floods. A water-damage disaster physical model was established to investigate the characteristics of the riverbed scour profile and the pipeline force when the pipeline was buried at different depths under the condition of different particle size riverbed sediment. Results indicated that the equilibrium scour depth changed in a spoon shape with the gradual increase of the embedment ratio in general. The equilibrium scour depth formed by the fine sand riverbed was the largest, about 1.5 times the pipeline diameter. When the pipeline was half exposed, the clay riverbed was more resistant to the scour of the river than the riverbed of fine sand and very fine pebbles with a larger particle size. In the riverbed of three particle sizes, fine sand was more difficult to withstand the scour of the river. The scour profile formed by the sand bed around the pipeline and the force and deformation of the pipeline were related to pipeline location and riverbed sediment type. Results of this study might be useful for the safety warning and protection measures of underwater pipeline crossing.

To study the influence of coal mining on the porosity of shallow sandy loam under conditions of shallow seam mining in thick, loose layers in north-west China, a typical surface sandy loam stratum in Shaanxi Province was taken as the study area, and experiments were performed to test the variation of soil porosity at different depths of 0–10 m in strata before, during and after mining therein. The experimental results demonstrate that the overall average porosities in the disc-shaped edge area, the disc-shaped edge area to the disc-shaped basin bottom area and the disc-shaped subsidence centre area of shallow sandy loam in mining increased by (23.51, 18.07 and 22.61%) respectively compared with that before mining. Mining meant that the soil porosity in the period of stable subsidence after mining changed significantly in the disc-shaped edge area and the disc-shaped edge to the disc-shaped basin bottom area. The disc-shaped edge area shows a trend of slowly rising porosity with the increase of depth, and the disc-shaped edge area to the disc-shaped basin bottom area shows a trend of gradually increasing first and then gradually becoming stable. Although the porosity in the central area of disc-shaped subsidence increased before mining, its trend was similar to that before mining. Although the change in soil porosity in the period of post-mining settlement stability is greater than that before mining, it is best fitted by a quintic polynomial. In general, the rate of change of soil porosity in the study area shows similar trends with depth. It showed a U-shaped variation that first decreased, stabilised for a distance and then gradually increased. This study provides theoretical support for surface soil remediation and ecological environment restoration in coal mining areas.

Abstract In this paper, we consider the q-difference equation (f(qz)+f(z))(f(z)+f(z/q))=R(z,f), $$ \bigl(f(qz)+f(z)\bigr) \bigl(f(z)+f(z/q)\bigr)=R(z,f), $$ where R(z,f) $R(z,f)$ is rational in f and meromorphic in z. It shows that if the above equation assumes an admissible zero-order meromorphic solution f(z) $f(z)$, then either f(z) $f(z)$ is a solution of a q-difference Riccati equation or the coefficients satisfy some conditions.

The reaction of enamine compounds with the Togni reagent in the presence of CuI afforded β-trifluoromethylated enamine intermediates, which were converted directly to biologically interesting trifluoromethylated 2H-azirines by an iodosobenzene (PhIO)-mediated intramolecular azirination in a one-pot process.

Abstract In this paper, we investigate the difference Painlevé III equations w(z+1)w(z−1)(w(z)−1)2=w2(z)−λw(z)+μ $w(z+1)w(z-1)(w(z)-1)^{2}=w^{2}(z)-\lambda w(z)+\mu$ ( λμ≠0 $\lambda\mu\neq 0$) and w(z+1)w(z−1)(w(z)−1)2=w2(z) $w(z+1)w(z-1)(w(z)-1)^{2}=w^{2}(z)$, and obtain some results about the properties of the finite order transcendental meromorphic solutions. In particular, we get the precise estimations of exponents of convergence of poles of difference Δw(z)=w(z+1)−w(z) $\Delta w(z)=w(z+1)-w(z)$ and divided difference Δw(z)w(z) $\frac{\Delta w(z)}{w(z)}$, and of fixed points of w(z+η) $w(z+\eta)$ ( η∈C∖{0} $\eta\in C\setminus\{0\}$).

Cold fronts, as one of the most frequent extreme weather events, can induce significant waves on the sea. This work analyzes the spatial and temporal variations in cold front events, especially the characteristics of wind directions during cold fronts in the East China Sea (ECS). The SWAN (Simulating Waves Nearshore) model is applied to simulating the waves induced by cold fronts. To calibrate the model, two typical cold front events were selected to simulate the corresponding waves in the ECS. The results indicate that the data misfit between the observed and modeled significant wave heights (SWH) is within a reasonable range. Idealized sensitivity experiments were then designed in order to analyze and discuss the responses of ocean waves to wind direction, swell distribution, maximum of significant wave heights (MSWH), and time lag during the cold fronts. The results show that the average MSWH in the ECS decreases monotonically with the deflection of wind direction from north-east to north-west, while specific nearshore sites do not conform to this pattern due to topography. The time series of SWH indicate that the action of the swells leads to a prolongation of the duration of catastrophic waves. This work investigates the temporal and spatial distribution characteristics of cold front-induced wind wave fields in offshore Zhejiang, which has important value for the study of the impact of cold fronts on the ocean as well as disaster prevention and mitigation efforts.

Using NiCl2 and NaOH as raw materials, stacked Ni(OH)2 hexagonal nanoplates with different edge lengths were prepared in a large scale by a simple hydrothermal route. The stacked Ni(OH)2 structure was composed of a certain amount of parallel Ni(OH)2 hexagonal nanoplates along the (001) direction. Each parallel Ni(OH)2 nanoplate had a single-crystal structure, and the exposed planes were (001), (00−1), and (100). The formation mechanism of the stacked Ni(OH)2 structures was discussed on the basis of the Ni(OH)2 crystal structure.

Abstract In this paper, we investigate the admissible entire solutions of finite order of the differential-difference equations ( f ′ ( z ) ) 2 + P 2 ( z ) f 2 ( z + c ) = Q ( z ) e α ( z ) $(f'(z))^{2}+P^{2}(z)f^{2}(z+c)=Q(z)e^{\alpha(z)}$ and ( f ′ ( z ) ) 2 + [ f ( z + c ) − f ( z ) ] 2 = Q ( z ) e α ( z ) $(f'(z))^{2}+[f(z+c)-f(z)]^{2}=Q(z)e^{\alpha(z)}$ , where P ( z ) $P(z)$ , Q ( z ) $Q(z)$ are two non-zero polynomials, α ( z ) $\alpha(z)$ is a polynomial and c ∈ C ∖ { 0 } $c\in\mathbb{C}\backslash\{0\}$ . In addition, we investigate the non-existence of entire solutions of finite order of the differential-difference equation ( f ′ ( z ) ) n + P ( z ) f m ( z + c ) = Q ( z ) $(f'(z))^{n}+P(z)f^{m}(z+c)=Q(z)$ , where P ( z ) $P(z)$ , Q ( z ) $Q(z)$ are two non-constant polynomials, c ∈ C ∖ { 0 } $c\in\mathbb{C}\backslash\{0\}$ , m, n are positive integers and satisfy 1 m + 1 n < 2 $\frac{1}{m}+\frac{1}{n}

The variations and dynamics of suspended sediment in the coastal waters around the Zhoushan Archipelago are complex due to strong tidal dynamics. This study aims to delineate the tide-induced variability of surface suspended sediment and reveal its mechanisms in the Zhoushan Archipelago based on Geostationary Ocean Color Imager (GOCI) data. Suspended sediment concentration (SSC) estimations through the ultraviolet wavelength atmospheric correction (UV-AC) algorithm and a tuned empirical inversion algorithm using extensive in situ measurements are presented. GOCI-processed remote sensing reflectance (Rrs) is validated using field data and is cross-validated with Landsat 8 Operational Land Imager (L8/OLI) measurements, respectively. The estimated SSC is validated with independent datasets. The validations reveal that GOCI-processed Rrs is reasonable and that the GOCI-retrieved SSC is accurate and can be used to quantify SSC distributions and variations in the Zhoushan Archipelago. The variations of the SSC in the study area are closely related to the temporal variations of the tidal level. High SSCs often occur in the middle of ebb or flood tides due to large tidal discharge and high tidal velocity. Significant hourly variations of the SSC are mainly controlled by tidal forces. Dynamic mechanism analysis indicates that during neap and middle tides, the local high SSC is mainly attributed to the sediment resuspension process driven by tidal currents; in addition, during the spring tide, the variations of the SSC are simultaneously modulated by sediment resuspension and horizontal advection processes.

Shallow-buried high-intensity mining (SHM) activities commonly in China’s western mining area will lead to the decrease of groundwater level and soil water content (SWC), which will aggravate the further deterioration of the local fragile ecological environment. In this study, the applicability and limitations of six typical soil dielectric models were comprehensively evaluated based on ground penetrating radar (GPR) technology and shallow drilling methods. Moreover, experiments were performed to test the variation of SWC in Ningtiaota minefield affected by the SHM. The results show that the fitting effect of the four empirical models and two semi-empirical models on the clay is better than that of the medium sand. Among the six models, the Ledieu model has the best performance for medium sand, and the Topp model for clay. After SHM, the shallow SWC decreases as a whole. The decreasing range is 4.37–15.84%, showing a gradual downward trend compared with the one before mining. The shorter the lagging working face distance, the greater the drop of SWC will be. The longer the lagging working face distance, the smaller the drop of SWC will be showing a gradual and stable trend.

Big data, cloud computing, and high-performance computing (HPC) are at the verge of convergence. Cloud computing is already playing an active part in big data processing with the help of big data frameworks like Hadoop and Spark. The recent upsurge of high-performance computing in China provides extra possibilities and capacity to address the challenges associated with big data. In this paper, we propose Orion—a big data interface on the Tianhe-2 supercomputer—to enable big data applications to run on Tianhe-2 via a single command or a shell script. Orion supports multiple users, and each user can launch multiple tasks. It minimizes the effort needed to initiate big data applications on the Tianhe-2 supercomputer via automated configuration. Orion follows the “allocate-when-needed” paradigm, and it avoids the idle occupation of computational resources. We tested the utility and performance of Orion using a big genomic dataset and achieved a satisfactory performance on Tianhe-2 with very few modifications to existing applications that were implemented in Hadoop/Spark. In summary, Orion provides a practical and economical interface for big data processing on Tianhe-2.