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Earth's thermo-tectonic evolution determines the way the planet's interior and surface interact and shows temporal changes in both trends and periodic rhythms. By sampling the subcontinental lithospheric mantle that represents the interface between the convecting mantle and the crust, carbonatite and kimberlite should be ideal rock types for documenting this evolution. The first-order secular rise of kimberlites over time has been noted by researchers, but there is much debate over how to interpret this trend, and their second-order variability has received less attention. We compiled a comprehensive global carbonatite database and compared it with an existing kimberlite one. We find that the numbers of carbonatites and kimberlites have similar increasing secular trends, with accelerated growth after ca. 1 Ga, and show the same periodic rhythms that have been synchronized to the supercontinent cycle since ca. 2.1 Ga. We link these trends and rhythms to the long-term change of Earth and the supercontinent cycle, both of which have altered the temperature of, and the subduction-recycled volatile flux into, the subcontinental lithosphere. Such consistent records in carbonatite and kimberlite behavior provide critical evidence for the synchronous thermo-tectonic evolution of the entire subcontinental lithosphere.

Coal and gas outburst is one of the main disasters that seriously threaten workers’ safety during coal production. Timely identification and evaluation of the potential outburst before tunneling helps to implement the targeted control measures. Nevertheless, the influencing factors of outburst are so complex that there is no suitable index system and evaluation method available yet. In this paper, a more reasonable and complete index system (three categories of factors and 16 indicators) for outburst risk is established, in which, the risk level is divided into three levels. Then, the triangular fuzzy numbers are adopted to quantify the indicators and the logarithmic fuzzy preference programming method to calculate the weight. The cloud distribution under finite interval processing is generated based on cloud numerical characters of each indicator. In addition, the risk level is determined according to the calculation results of multi-index comprehensive membership degree. Finally, the entire evaluation system is applied to two excavated coal roadways for experiments, which show that the finite interval cloud model delivers a more objective and reasonable risk assessment. Five potential outburst threat areas of 58 excavation cycles evaluated show different degrees of outburst dynamic appearance, indicating a good relationship between the evaluation results and the actual risk. This method effectively considers the fuzziness and randomness between indexes, and it is able to classify outburst risk effectively, providing insights for the scientific and accurate assessment of such risks in front of the driving face.

Present work aimed at studying the effect of montmorillonite (MMT) on dielectric and conductive properties of composites based on polymer/hafnium carbide (HfC) mother composite system. Polymer/HfC/MMT composite films based on double-filler modification strategy were prepared by solution cast. To obtain control group, binary polymer/HfC composite films were prepared. MMT ceramic had excellent insulation property, which could suppress interface leakage current and thus reduce dielectric loss of composites. Compared with binary system, ternary system could show better overall electric features including mildly reduced permittivity, obviously reduced dielectric loss and conductivity. Optimized ternary composite bearing 3 wt% HfC and 3 wt% MMT exhibited a high permittivity of 34, low dielectric loss of 0.33 and low conductivity of 5.5 × 10−7 S m−1 at 100 Hz. This research might enable the fabrication of advanced composite dielectrics.

Unequal breeding sex ratio can significantly reduce effective population size, allowing a rare neutral allele to jump to a high frequency through genetic drift. However, this one-way alteration to allele frequency appears inconsistent with the concept that drift is non-directional. Based on binomial sampling distribution, this study developed a method to directly and exhaustively measure drift by calculating the mean deviation of change in allele frequency, then applied it to cases of unequal breeding sex ratio. The result shows that, under those cases, (1) the mean deviation can always be divided into two halves that are equal in size but opposite in direction; (2) each half consists of one or several categories represented by various allele proportions in the rare sex; (3) this proportion is another factor that determines the outcome of drift, in addition to effective population size and allele frequency; (4) drift is non-directional on a global scale, but whether an allele will drift up or down can be predicted based on the above factors. This method enables us to dissect every component of the expected change in allele frequency caused by drift and to find out the combined effect of population size, allele frequency and allele proportion in the rarer sex under neutrality but unequal breeding sex ratio.

Polymer/conductor composite dielectrics easily have high permittivity, high conductivity, and high dielectric loss, limiting large increase of energy storage density in them. The relationship between high permittivity and low conductivity is coordinated to achieve high energy density. In this study, polyvinyl alcohol (PVA)/V2C MXene/cellulose ternary composites with high permittivity and low dielectric loss were prepared. Due to good water solubility of PVA and high water dispersibility of V2C, PVA and V2C have good interfacial compatibility. That reduces the interface electric leakage conductance, which is conducive to the lower conductivity and dielectric loss in the composite materials. The high interfacial polarization between PVA and V2C improves the dielectric response of the composite materials, improving the permittivity of the composite materials. Compared with binary PVA/V2C composites, ternary PVA/V2C/cellulose composite materials use the high insulation of cellulose filler to increase the insulation of composites. Thus, the conductivity and dielectric loss are reduced in ternary composites. Good synergy of conductive V2C and insulating cellulose fillers is important to obtaining the balance of high dielectric response and high insulation trait in ternary composites. Best ternary composite with 6 wt% V2C has a high permittivity of ca. 40, low dielectric loss of ca. 0.25 at 100 Hz, and high breakdown strength of ca. 40 MV m−1. This work enables a facile preparation of promising composites for dielectric energy storage. • Novel ternary composite dielectric films with V 2 C MXene and cellulose were fabricated. • Good synergy of V 2 C and cellulose can lead to optimization of overall electric properties. • This work might provide ideas for preparing bio-dielectric materials employing cellulose.

Two new aspidosperma-type monoterpenoid indole alkaloids, 16

Carbonate clumped isotope (Δ47) is a new and reliable geothermometer. Endogenic carbonates in lake sediments are good archives to reconstruct lake water temperature using clumped isotope thermometry. However, applications of carbonate clumped isotope thermometry to lacustrine carbonates are still scarce because the existed organic and/or sulfur contaminants in such samples interfere with clumped isotope analysis and cause notable temperature biases. Therefore, exploring an effective way to remove contamination is a prerequisite to widely applying carbonate clumped isotope thermometry to lake sediments. By pretreating fine-grained endogenic carbonates from Dali lake sediments with hydrogen peroxide of different concentrations for different lengths of time, we conducted a series of conditional experiments to seek the optimal pretreatment condition for clumped isotope analysis. Δ47, Δ48 offset and 49 parameter were obtained from clumped isotope measurements to assess the effect of contamination removal. Results showed that untreated samples (“0%-0”) had a very high 49 parameter. After the treatment with hydrogen peroxide, the 49 parameter was significantly reduced while the Δ48 offset evidently increased. The Δ47 , Δ48 offset and 49 parameter of samples pretreated under different conditions showed significant variability, even though the measured Δ47 temperatures changed within a relatively narrow range (i.e., from 17.0±1.3 to 22.8±1.6°C). Among various treated samples, the sample “3%-8” yielded a smaller Δ48 offset and 49 parameter, and lower Δ47 temperature of 17.0±1.3°C. Therefore, “reacting with 3% hydrogen peroxide for 8 h” was suggested to be the optimal condition for removing contaminants from lacustrine endogenic carbonates prior to clumped isotope analysis. At the time when the pretreatment condition was too intense (i.e., H2O2 concentration >3% and/or reaction time > 8 h), secondary contaminants might have been generated in the closed reaction system, whose ultimately transformed state may interfere with masses 47, 48. Using the optimal pretreatment procedure, we obtained reasonable Δ47 temperature changes during the last deglaciation and found a temperature decrease of about 6°C in Northern China during the Younger Dryas period. Our study demonstrates a great potential of applying carbonate clumped isotope thermometry to lacustrine carbonates for paleo-temperature and paleo-elevation reconstructions in the future.

High-dielectric-constant (high-k) polymer/conductor composites with low dielectric loss are desirable for energy storage. However, high leakage currents from interfacial regions with high charge density are difficult to handle. In this work, high permittivity and low dielectric loss were achieved in poly(vinyl alcohol) (PVA)/V2C MXene nanocomposite films fabricated by solution casting by taking advantage of the interfacial compatibility and moderate interfacial charge density of the nanocomposites. Water-soluble PVA was utilized as the polymer matrix. Delaminated V2C MXene nanosheets with appropriate conductivity were prepared and used as the filler. The mild interface polarization of the nanocomposites was responsible for achieving favourable permittivity values. The small gap between the work functions of PVA and V2C contributed to moderate interfacial charge density values and thus low dielectric loss values. A proportional correlation between the interfacial charge density and the conductivity of composites was also verified. The depth of charge injection from the MXene to PVA was found to be half of the interlamellar spacing of the delaminated MXene. The dependence of the electrical properties of the nanocomposites on the frequency and MXene content was also studied. The composite with 4 wt% MXene exhibited a permittivity of ~24 (16 times that of PVA) and a dielectric loss of ~0.14 (1.5 times that of PVA) at 1 kHz, as well as breakdown strength of ~31 MV m−1 (63% of PVA). This work might enable environmentally friendly fabrication of promising composite dielectrics.

When it comes to estimating the magnitude of genetic drift, there is hardly any indexes other than the effective population size. Starting from the binomial sampling distribution, this research proposed using mean deviation of allele frequency change as a direct measurement of drift, then tested it in a classical example concerning unequal breeding sex ratio. This study found that: (1) mean deviation offers a new dimension in measuring the magnitude of drift; (2) the measurement displays a “half-half” pattern; (3) allele frequency determines the efficacy of hitchhiking effect of rare alleles, and in what way that “half-half” pattern should be divided.

Two new aspidosperma-type monoterpenoid indole alkaloids, 16-O-methylvoafinine (1) and 14,15-diepi-voafinidine (2) were isolated from the aerial parts of Ervatamia officinalis. Their structures were established by comprehensive spectroscopic analysis including 1D and 2D NMR, HR-ESI-MS, and electronic circular dichroism calculation. The isolated compounds were evaluated for cytotoxic activities against HepG2, MCF-7, and A549 cell lines by CCK-8 assay.

Dataset 1 Parent dataset of global mantle clinopyroxene compositions. Dataset 2 Labeled dataset for training the ML model to classify clinopyroxene compositions as affected or unaffected by metasomatism. Dataset 3 Application dataset. For details, please see the corresponding manuscript that describes the study and readme txt in the dataset file., For more details and updated version code see https://github.com/ZJUEarthData/BenQin_mantle-matesomatism-machine-learning

Land snail fossils are abundantly distributed in geological deposits and their isotopic compositions provide a means to determine paleoclimatic changes. With the development of the clumped isotopes (Δ47) geothermometer, many efforts have been made in recent years to study clumped isotopes in land snail shell carbonate. Although there have been several recent attempts, there is, as yet, no empirical calibration function to convert land snail Δ47 to environmental temperature. Here, we systematically analyzed clumped isotopes (Δ47) of two common land snail species (Bradybaena and Cathaica) from China. Results showed that temperatures calculated using the Δ47 (T47) of both species did not correlate with the mean annual temperatures (MAT) at the study sites. However, the T47-MAT offset is negatively correlated to MAT, suggesting that land snails tend to add shell during the warmer months at colder sites or modulate their body temperature differently in colder regions. Meanwhile, clumped temperatures of Cathaica are 3.4 ± 1.5 °C higher than those of Bradybaena at 18 sites, indicating that a species-specific transfer function is needed to reconstruct paleotemperature using land snail clumped isotopes. After determining the proper duration of the growing season for land snails at different locations, we developed a Δ47-growth season temperature (GST) transfer function for the two species. The calibration function for Bradybaena land snails is expressed by a linear regression between 1/T2 and absolute Δ47 (R2 = 0.94): Δ47 = (0.0513 ± 0.0036) × 106/T2 + (0.0930 ± 0.0413), where Δ47 is expressed in ‰ and T in K. The calibration function for Cathaica is as follows (R2 = 0.80): Δ47 = (0.055 ± 0.011) × 106/T2 + (0.035 ± 0.129). The function for Cathaica was successfully applied to reconstruct mean summer (June-July-August) temperatures during the Last Glacial Maximum and modern times on the central Chinese Loess Plateau, based on Δ47 data of Cathaica sp. provided by Eagle et al (2013a). This testifies to the validity of the aforementioned constructed transfer function. In addition, the calculated δ18O of body water (δ18OBW) for Bradybaena showed a robust correlation with the δ18O of rainfall (δ18Op), particularly in northern China, which points to the potential to trace hydrological changes in the region. In contrast, Cathaica δ18OBW did not show a straightforward relation to δ18Op. This inter-species complexity warrants further study.

A contradiction between high permittivity and breakdown strength has long been problematic for obtaining high energy density in conductor/polymer composites. Recently, a gradient-sandwich strategy has been employed to achieve favorable dielectric and breakdown properties in metallic inorganic nanoparticles filled polymer nanocomposites. However, a desirable high breakdown strength cannot be retained once the filler concentration is further increased. In this work, metallic TaB2@semiconducting Ta2O5 nanoparticles were employed to prepare polyvinylidene fluoride (PVDF) nanocomposites with a gradient-sandwich construction to induce an interface barrier effect for depressing the growth of electric trees. Interface polarization (between Ta2O5 and PVDF) and interface barrier (between two adjacent sub-layers) effects contributed to an elevation of the permittivity and breakdown strength, respectively. The novelty lies in utilizing the Schottky barrier effect (between Ta2O5 and TaB2) to simultaneously improve the permittivity and breakdown strength of the composites based on the TaB2 electron-trap and induced electron–hole dipoles. A combination of triple effects (Schottky barrier, interface barrier and interface polarization effects) resulted in high permittivity and breakdown strength at the same time. Tri-effect cooperation from the core–shell filler, gradient sandwich structure and organic–inorganic blend was helpful to decrease the temperature-dependence of the electrical properties, increase the electric insulation at high applied field and elevate the dielectric tunability. The comprehensive electric performances of two composite systems filled with TaB2@Ta2O5 and TaB2 were compared. The superiority of the core–shell filler was confirmed. A high breakdown strength of ∼286 MV m−1 and permittivity of ∼126 @ 1 kHz were achieved. This work might open up a door to large-scale preparation of high-performance nanocomposite dielectrics.

Composite dielectrics with high permittivity, low dielectric loss and low conductivity are desired. Low loss and low conductivity are difficult to achieve due to the poor interfacial compatibility and high leakage conductance. In this work, polymer/ionic liquid (IL)/hexagonal boron nitride (h-BN) nanocomposites were fabricated. A synergy between IL and BN was found. The blocked conductive path and reduced dipole coupling contributed to reduced loss and conductivity. Polyvinylidene fluoride (PVDF) was used as the polymeric matrix. The 1-butyl-3-methylimidazolium hexafluorophosphate IL with a high interface compatibility onto PVDF was employed as an organic filler. The ultrahigh polarity of IL contributed to the improved permittivity. BN, with an ultrahigh insulation property, was utilized as an inorganic filler. The BN could block the conductive path and reduce the coupling between the ionic dipoles in the IL. Compared with PVDF/IL composites, the ternary composites showed improved overall electrical properties. The ternary composite with 1.5 wt % IL and 5.0 wt % BN had a high permittivity of ∼46, low loss of ∼0.23 and low conductivity of ∼2.49 × 10−7 S m-1 at 100 Hz. This work might offer the design ideas for the promising composite dielectrics.

Ervaoffine E (1), a new pseudoindoxyl alkaloid possessing a unique rearranged 1,4-diazacycloheptane skeleton, ervaoffine F (2), the first 5,6-seco-6-nor iboga-type alkaloid featuring ring C cleavage, and ervaoffine G (3), bearing an unusual contracted valerolactam ring, together with six known alkaloids were isolated from Ervatamia officinalis. Their structures and absolute configurations were determined by extensive spectroscopic analysis, single-crystal X-ray diffraction and quantum chemical ECD calculations. Plausible biogenetic pathways of these new alkaloids were also proposed and provided new insights into the structural plasticity of ring C in iboga-type alkaloids. Compound 3 exhibited a significant neuroprotective effect against oxygen-glucose deprivation (OGD)-induced damage of cultured cortical neurons, an in vitro model of ischemic stroke.

Bismuth ferrite (BiFeO3) acting as a significant multiferroic material exhibits unique magnetic and ferroelectric properties. Here we report the size-controlled synthesis of BiFeO3 nanoparticles via a facile and stable Pechini sol–gel method, in which uses tartaric acid as a complexing agent, ethylene glycol as a polymerizing agent. It is found that the nanoparticle size is sensitive to the gel-forming temperature. The nanoparticles with size as small as 30 nm have been obtained. A sequential reaction process and the mechanism of size controllable growth of BiFeO3 has been presented. The effects of size on optical and magnetic properties have been also investigated. The decreasing particles lead to blue shift in the band gap. BiFeO3 nanoparticles show weak ferromagnetic character due to a Fe3+ oxidation state, and the magnetization increases with decrease in the particle size.

It is known that CH3NH3PbI3 perovskite films with high crystallization and controlled morphology always show enhanced power conversion efficiency. Here we incorporate a small amount of polyvinylidene fluoride–trifluoroethylene polymer P(VDF-TrFE) into PbI2 solution to control the crystallinity and morphology of perovskite layer in a two-step deposition process. Our results show that the P(VDF-TrFE) bridges the grain boundaries and also enhances the crystallinity of the perovskite layer significantly. By adjusting P(VDF-TrFE) concentration, the fabricated perovskite solar cells show improved average power conversion efficiency from 9.57 ± 0.25% to 12.54 ± 0.40% under a standard illumination of 100 milliwatts per square centimeter, which increases by nearly 31%. Thus, we demonstrate a new strategy to control the crystallinity and morphology of perovskite films by incorporating polymer into PbI2 film in a two-step deposition process. In addition, this method has been proven as an effective way to prepare hig...

The analysis of the characteristics and footprint climatology of farmland water and heat fluxes has great significance to strengthen regional climate resource management and improve the hydrothermal resource utilization in the region of red soil. Based on quality controlled data from large aperture scintillometer and automatic meteorological station in hilly region of red soil, this paper analyzed in detail the characteristics of farmland water and heat fluxes at different temporal scales and the corresponding source area distribution of flux measurement in the non-rainy season and crop growth period in hilly region of red soil. The results showed that the diurnal variation of water and heat fluxes showed a unimodal trend, but compared with the sunny day, the diurnal variation curves fluctuated more complicatedly on cloudy day. In the whole, either ten-day periods or month scale, the water and heat fluxes were greater in August than in September, while the net radiation flux was more distributed to latent heat exchange. The proportion of net radiation to latent heat flux decreased in September compared to August, but the sensible heat flux was vice versa. With combined effects of weather conditions (particularly wind), stability, and surface condition, the source areas of flux measurement at different temporal scales showed different distribution characteristics. Combined with the underlying surface crops, the source areas at different temporal scales also had different contribution sources.农田水热通量的变化特征以及气候学足迹分析对加强区域气候资源管理和提高红壤地区水热资源利用率有重要意义.利用低丘红壤区的大孔径闪烁仪和自动气象站数据,在保证数据质量的基础上,详细分析了低丘红壤区农田在非雨季、作物生长旺期不同时间尺度水热通量的变化特征和观测通量的源区分布特征.结果表明: 水热通量的日变化呈单峰型,但与晴天相比较,多云天的日变化曲线波动更为复杂;无论是旬尺度还是月尺度, 8月的水热通量整体上都大于9月,且净辐射通量都更多地用于潜热交换,但9月潜热通量所占净辐射比例相较于8月有所减少,感热通量则相反;受气象条件(尤其是风)、稳定度和下垫面状况影响,不同时间尺度的观测通量源区特征不同;结合下垫面作物来看,不同时间尺度源区的通量贡献来源也不同.

Five novel compounds, including four neoclerodane diterpenoids, named ajugacumbins KN (1-4) along with a phytoecdysterone, named ajugacetalsterone E (5), were isolated from the whole herbs of Ajuga decumbens (Labiatae). Their structures were elucidated on the basis of detailed spectroscopic analysis including IR, HRESIMS, CD, 1D and 2D NMR spectroscopic experiments. Compounds 1-5 were evaluated for their cytotoxic activities and the effects on superoxide anion generation and elastase release in FMLP/CB-induced human neutrophils.

Anstifolines A and B, two dimeric furoquinoline alkaloids with unique coupling patterns were isolated from the root bark of Dictamnus angustifolius. The biosynthetic pathway of anstifoline A was proposed. All of the isolates exhibited cytotoxicities and inhibition of superoxide anion generation and elastase release.

Two pairs of new enantiomeric benzofurans with unusual skeletons, (+)- and (−)-eupachinin A (1), as well as (+)- and (−)-eupachinin B (2), were isolated from the roots of Eupatorium chinense by chiral HPLC. Their structures with absolute configurations were elucidated on the basis of spectroscopic methods, X-ray diffraction analysis, and quantum chemical calculation. The plausible biogenetic pathway of 1 and 2 was also proposed.

Three novel limonoids, dictangustone G (1), dictangustone H (2), and dictangustone I (3) were isolated from the root bark of Dictamnus angustifolius. Their structures were elucidated on the basis of detailed spectroscopic analysis including UV, IR, HRESIMS, 1D and 2D NMR spectroscopic experiments. Compounds 1–3 were evaluated for their cytotoxic activities using Hela, A549, MCF7, and LN229 cell lines.

Anstifolines A (I) and B (II) are isolated together with two known compounds, dictamnine and robustine.

In this paper, the feasibility of preparing activated carbon from corncob furfural residue with ZnCl2 by microwave irradiation was studied. The effect of the ratio by weight of ZnCl2 to corncob furfural residue, ZnCl2 solution soaking time, microwave irradiation time and the pH value of ZnCl2 solution on the quality of activated carbon was investigated. On the condition that the microwave power is 800 W and ZnCl2 solution mass concentration is 50%, the best technological parameter on preparing activated carbon with ZnCl2 by microwave irradiation is obtained: at the ratio of 3.5:1 by weight of ZnCl2 to corncob furfural residue, microwave irradiation time is 20 min, ZnCl2 solution soaking time is 12 h, the pH value of ZnCl2 solution is 2, the activated carbon yield reached 33.1% and the decolorizing capacity for methylene blue is 202.5 mg/g, the product is used in treating Cr6+ solution(pH value 4.0, concentration 50 mg/L), its adsorption capacity of Cr6+ is 7.583 mg/g.

A new cycloartane-type triterpenoid, named 22-hydroxy-cyclolaudenol (1), together with two known cycloartane-type triterpenoids were isolated from the roots of Dianella ensifolia. Their structures were determined based on spectroscopic methods, including UV, IR, HR-ESI-MS, NMR and X-ray diffraction. Compound 1 displayed cytotoxic effects against cancer cell lines B16-F10, A549 and MDA-MB-231.

Ervahainine A ( 1 ), a new cyano-substituted oxindole alkaloid, was isolated from Ervatamia hainanensis . The structure was elucidated on the basis of spectroscopic methods and further confirmed by the single-crystal X-ray diffraction analysis. Ervahainine A exhibited potential inhibition against two human cancer cell lines.

Seven new iboga-type alkaloids, ervaoffines A–D (1–4), (7S)-3-oxoibogaine hydroxyindolenine (5), ibogaine-5,6-dione (6), and 19-epi-5-oxovoacristine (7), and 10 known alkaloids were isolated from Ervatamia officinalis. The absolute configurations of 1–7 were determined through X-ray diffraction and electronic circular dichroism (ECD) analyses. Ervaoffines A and B represent the first iboga-type pseudoindoxyl alkaloids in which the C-2 spiro carbon configuration is opposite to that of other members of this class, such as iboluteine (8). The relationship between the absolute configuration of the spiro carbons and the Cotton effect in the ECD spectrum is established for the first time for iboga-type pseudoindoxyl and oxindole alkaloids. Additionally, a plausible biogenetic pathway for these alkaloids is proposed.

To investigate effect of particle size on oral absorption of silymarin-loaded solid lipid nanoparuicles.Solid lipid nanoparticles (SLN) of various sizes (150 nm, 500 nm and 1000 nm) using Compritol 888 ATO as the material and silymarin (SM) as a model drug were prepared. Silybinin concentration in plasma of rats were determined by RP-HPLC with UV detector. The main pharmacokinetic parameters were calculated by 3p97.Results showed that the AUC of 150 nm SLN was 2.08 fold that of 500 nm SLN and 2.54 fold of 1000 nm SLN treated orally to rats (P0.05). The oral bioavailability of 150 nm SLN was remarkably higher than the other two size SLN.This has important implications in designing of SM-SLN as a new oral drug delivery system.