Quantitative Study on Morphological Change Characteristics of Tonle Sap Lake Based on DEM

Lake is an important part of the natural ecosystem, and its morphological characteristics reflect the capacity of lake regulation and storage, the strength of material migration, and the characteristics of shoreline development. In most existing studies, remote sensing images are used to quantify the morphological characteristics of lakes. However, the extraction accuracy of lake water is greatly affected by cloud cover and vegetation cover, and the inversion accuracy of lake elevation data is poor, which cannot accurately describe the response relationship of lake landscape morphology with water level change. Therefore, this paper takes Tonle Sap Lake as the research object, which is the largest natural freshwater lake in Southeast Asia. DEM is constructed based on high-resolution measured topographic data, and morphological indicators such as lake area, lake shoreline length, perimeter area ratio, longest axis length, maximum width, shoreline development index, lake shape complexity, compactness ratio and form ratio are adopted to researching the evolution law of high water overflows and low water outbursts quantitatively, and clarifying the variation characteristics of landscape morphology with water level gradient in Tonle Sap Lake. The research results have important theoretical significance for the scientific utilization of Tonle Sap Lake water resources and the protection of the lake ecosystem.

Effect mechanism of seepage force on the hydraulic fracture propagation

The flow of fluid through the porous matrix of a reservoir rock applies a seepage force to the solid rock matrix.Although the seepage force exerted by fluid flow through the porous matrix of a reservoir rock has a notable influence on rock deformation and failure,its effect on hydraulic fracture(HF)propagation remains ambiguous.Therefore,in this study,we improved a traditional fluid–solid coupling method by incorporating the role of seepage force during the fracturing fluid seepage,using the discrete element method.First,we validated the simulation results of the improved method by comparing them with an analytical solution of the seepage force and published experimental results.Next,we conducted numerical simulations in both homogeneous and heterogeneous sandstone formations to investigate the influence of seepage force on HF propagation.Our results indicate that fluid viscosity has a greater impact on the magnitude and extent of seepage force compared to injection rate,and that lower viscosity and injection rate correspond to shorter hydraulic fracture lengths.Furthermore,seepage force influences the direction of HF propagation,causing HFs to deflect towards the side of the reservoir with weaker cementation and higher permeability.

葡萄糖糖化血红蛋白与纤维蛋白原检测在2型糖尿病眼部微血管病变中的应用价值

目的探讨糖化血红蛋白(HbA1c)联合纤维蛋白原(FIB)检测在2型糖尿病(T2DM)眼部微血管病变诊断价值。方法检测T2DM合并眼部微血管病变(A组)及眼部无微血管病变患者(B组)HbA1c及FIB水平并统计学分析。结果 A组HbA1c和F1B明显高于B组,两组有统计学差异(P<0.05);A组中HbA1c及FIB呈正相关,且明显高于B组(P<0.05)。HbA1c单项检测低于两者联合检测阳性率(P<0.05)。结论联合检测HbA1c和FIB对于早期诊断和治疗T2DM合并眼部微血管病变有重要价值。

Effect of composite supports on the methanation activity of Co-Mo-based sulphur-resistant catalysts

The effects of composite supports of CeO2-Al2O3, MgO-Al2O3, TiO2-Al2O3 or ZrO2-Al2O3 on the methanation activity of supported Co-Mo-based sulphur-resistant catalysts were investigated. The catalysts were further characterized by nitrogen adsorption measurement, X-ray diffraction and X-ray photoelectron spectroscopy. The catalyst of 5%CoO-15%MoO3 supported on CeO2-Al2O3, MgO-Al2O3, TiO2-Al2O3 or ZrO2-Al2O3 composite oxides, respectively, showed different catalytic performances of syngas methanation in the presence of hydrogen sulphide as compared with that of the 5%CoO-15%MoO3/Al2O3 catalyst. The Co-Mo/CeO2-Al2O3 catalyst shows the highest methanation activity among the tested catalysts. The enhanced methanation activity may be attributed to the improvement of the dispersion of active metal species and the inhibition of the formation of S6＋.

Correlation of the temporal and spatial expression patterns of HQT with the biosynthesis and accumulation of chlorogenic acid in Lonicera japonica flowers

Hydroxycinnamoyl-CoA quinate transferase(HQT)is one of the key enzymes in the biosynthesis of chlorogenic acid(CGA)in the flowers of Lonicera japonica.However,the spatiotemporal expression patterns of HQT and its relationship to the dynamics of CGA biosynthesis,transport,and storage remain largely unknown.In this study,we collected L.japonica flower samples at different growth stages(S1–S6)and examined the spatiotemporal expression pattern of HQT and the dynamic accumulation patterns of CGA using a combination of molecular and cytological techniques.Our results suggest that the spatiotemporal expression pattern of HQT is directly correlated with dynamic changes in CGA accumulation and distribution in L.japonica flowers.We further show that CGA is synthesized primarily in the cytoplasm and chloroplasts.CGA synthesized in the cytoplasm first accumulates in specialized vesicles and is then transferred to large central vacuoles for storage by fusion of CGA-containing vesicles with vacuoles.Furthermore,CGA synthesized in the chloroplasts appears to be transferred into the vacuoles for storage by direct membrane fusion between the tonoplast and the disrupted chloroplast membranes.Collectively,our results suggest that CGA is synthesized in chloroplasts and cytoplasm and finally transferred to the vacuole for long-term storage.

A low-jitter self-triggered spark-discharge pre-ionization switch: primary research on its breakdown characteristics and working mechanisms

MV pulsed switch plays a key role as the transfer switch in large electromagnetic pulse simulators. To broaden the range of self-triggering time, a novel spark-discharge pre-ionization switch, in which the main gap electric field is superposed at the trigger gap to let the electrons in its spark channel also become initial electrons, is proposed and tested. The design idea is: as electrons in the spark channel of the trigger gap always exist after its breakdown, the injection time of pre-ionization should have a more negligible effect on reducing the switch jitter. The experiment results under pulses with a rise time of ~100 ns support the above assumptions.When the operating voltage is from ~300 to ~800 kV and the self-triggering time is ~45% to~75% of the peak time, the breakdown time delay jitter is less than 2 ns, and the breakdown voltage jitter is smaller than 1.25%. Under specific self-triggering time, the breakdown time delay jitter is less than 1.5 ns, and the breakdown voltage jitter is smaller than 0.8%.

Mantle anisotropy across the southwestern boundary of the Ordos block,North China

Located at the northeastern margin of the Tibetan plateau,the Ordos block is a stable tectonic unit in North China.With its active boundary fault zones,the Ordos block played an important role in the eastward extrusion mechanism of the Tibetan plateau.Peking University deployed a linear array of 15 portable broadband seismometers across the western Weihe graben during September 2005 to August 2006 and later a 2-D seismic array（Southwest Ordos Array） of 14 portable broadband seismometers during 2007-2008 at its southwestern boundary.Analyses of shear wave splitting of SKS and SKKS phases at these stations show that the fast directions trend ～110° with an average delay time of 0.9 s in the southwestern margin of the Ordos block.The agreement between the lithosphere deformation indicated by GPS data and Quaternary fault slip-rate observations and the mantle flow represented by shear wave splitting implies that accordant deformation patterns from lithosphere to asthenosphere in relation to the eastward extrusion of the Tibetan plateau could extend at least to 200 km depth.Spatial distribution of splitting polarization directions indicates that the mantle flow driven by the Tibetan plateau is blocked by the Ordos block and locally restricted in a narrow channel along the Qinling-Dabie fault zones between the Ordos block and Sichuan basin.

A calculation model for breakdown time delay and jitter of gas switches under hundred-nanosecond pulses and its application in a self-triggered pre-ionized switch

In this paper, a calculation model for the breakdown time delay and jitter of gas switches under hundred-nanosecond pulses is proposed and applied in a self-triggered pre-ionized switch. The effects of injection time of pre-ionization, pulse rise time, and the pre-ionization jitter are discussed and verified through experiments. It indicates that the pre-ionization should be injected when the electric field is high enough in the gap, injection after 80% peak-time can ensure its effectiveness.Then the statistical time delay jitter will be determined by the pre-ionization jitter, which is an intrinsic restriction of the self-triggered switch. However, when the changing rate of the pulsed electric field exceeds a certain value, the breakdown time delay jitter can be partly offset in the formative stage because the formative time delay has an exponential relationship with the electric field. Therefore, lower time jitter can be obtained under pulses with a shorter pulse rise time. In general, the results of the calculation model agree with the experimental results, and the experimental parameters which lead to a low jitter can also be used as a reference.

Introduction to the special section:Recent advancement on integrated carbonate reservoirs prediction with complex secondary storage space

Carbonate reservoirs in Western China show tremendous exploration and development potential.These have become the key area for oil and gas reserves addition and sustainable resource development for China.Compared to conventional carbonate reservoirs,prediction of this kind of reservoir predominated by secondary storage is much more difficultand presents significant challenges.

Comparative study of pulsed breakdown processes and mechanisms in self-triggered four-electrode pre-ionized switches

This work investigates the pulsed breakdown processes and mechanisms of self-triggered preionized switches with a four-electrode structure in nitrogen through intensified charge coupled device photographs.The diameter of the trigger plane hole mainly determines the switch’s electric field distribution.Two configurations with minimum and maximum trigger plane holes are adopted for comparison.In the switch with a minimum trigger plane hole,the maximum electric field distributes at the surfaces of the main electrodes.Although charged particles in the triggering spark channel cannot drift out,homogeneous discharges can be stimulated from both the cathode and anode surfaces through ultraviolet illumination.Two sub-gaps are likely to break down simultaneously.In the switch with a maximum trigger plane hole,the maximum electric field locates near the trigger electrodes.Discharges in both sub-gaps initiate from the trigger electrodes in the form of a positive or negative streamer.Due to the lower breakdown voltage and electric field threshold for discharge initiation,the cathode side sub-gap breaks down first.The analysis of two extreme examples can be referenced in the future design and improvement of self-triggered four-electrode switches with different trigger electrode structures.

Breeding maize of ideal plant architecture for high-density planting tolerance through modulating shade avoidance response and beyond

Maize is a major staple crop widely used as food,animal feed,and raw materials in industrial production.High-density planting is a major factor contributing to the continuous increase of maize yield.However,high planting density usually triggers a shade avoidance response and causes increased plant height and ear height,resulting in lodging and yield loss.Reduced plant height and ear height,more erect leaf angle,reduced tassel branch number,earlier flowering,and strong root system architecture are five key morphological traits required for maize adaption to high-density planting.In this review,we summarize recent advances in deciphering the genetic and molecular mechanisms of maize involved in response to high-density planting.We also discuss some strategies for breeding advanced maize cultivars with superior performance under high-density planting conditions.

Uncovering the largest negative carbon isotope excursion in Earth history

The carbon cycle plays a pivotal role in regulating Earth’s surface environment through atmospheric-oceanic acid-base and redox processes, functioning as the engine driving the evolution of our planet’s surface. A deep understanding of the carbon cycle’s evolution is thus essential for our understanding of the evolution of our planet’s habitability.

Activable Photodynamic DNA Probe with an“AND”Logic Gate for Precision Skin Cancer Therapy

Photodynamic therapy(PDT)has emerged as a promising approach for squamous cell carcinoma treatment but hindered by tumor hypoxia,acquired resistance,phototoxicity,and so on.To address these issues,we developed a smart strategy utilizing activable photosensitizers delivered by an aptamer-functionalized DNA probe(ADP).The ADP incorporated an AS1411 aptamer for tumor targeting and a linear antisense oligonucleotide(ASO)for recognition of Survivin mRNA.In the absence of the target,PDT remained quenched,thereby avoiding phototoxicity during circulation and nonselective distribution.With the aid of the aptamer,ADP achieved selective targeting of tumors.Upon internalization,ADP targeted recognized Survivin mRNA,triggering PDT activation,and releasing ASO to down-regulate Survivin expression and reverse tumor resistance.Consequently,the activable photosensitizers exhibited an“AND”logic gate,combining tumor-targeting delivery and tumor-related gene activation,thus enhancing its specificity.Additionally,the incorporation of hemin into the ADP provided catalase activity,converting tumor-abundant H_(2)O_(2) into O_(2),thereby ameliorating tumor hypoxia.The resulting functionalized G-quadruplex/hemin–DNA probe complex demonstrated targeted delivery and activation,minimized side effects,and enhanced PDT efficacy in both xenograft tumor-bearing mice and patient-derived xenograft models.This study offers a unique and promising platform for efficient and safe PDT,thus holding great potential for future clinical translation and improved cancer therapy.

The RNA binding protein EHD6 recruits the m^(6)A reader YTH07 and sequesters OsCOL4 mRNA into phase-separated ribonucleoprotein condensates to promote rice flowering

N6-Methyladenosine(m^(6)A)is one of the most abundant modifications of eukaryotic mRNA,but its comprehensive biological functionality remains further exploration.In this study,we identified and characterized a new flowering-promoting gene,EARLY HEADING DATE6(EHD6),in rice.EHD6 encodes an RNA recognition motif(RRM)-containing RNA binding protein that is localized in the non-membranous cytoplasm ribonucleoprotein(RNP)granules and can bind both m^(6)A-modified RNA and unmodified RNA indiscriminately.We found that EHD6 can physically interact with YTH07,a YTH(YT521-B homology)domain-containing m^(6)A reader.We showed that their interaction enhances the binding of an m^(6)A-modified RNA and triggers relocation of a portion of YTH07 from the cytoplasm into RNP granules through phase-separated condensation.Within these condensates,the mRNA of a rice flowering repressor,CONSTANS-like 4(OsCOL4),becomes sequestered,leading to a reduction in its protein abundance and thus accelerated flowering through the Early heading date 1 pathway.Taken together,these results not only shed new light on the molecular mechanism of efficient m^(6)A recognition by the collaboration between an RNA binding protein and YTH family m^(6)A reader,but also uncover the potential for m^(6)A-mediated translation regulation through phaseseparated ribonucleoprotein condensation in rice.

Phytochrome B interacts with LIGULELESS1 to control plant architecture and density tolerance in maize

Over the past few decades,significant improvements in maize yield have been largely attributed to increased plant density of upright hybrid varieties rather than increased yield per plant.However,dense planting triggers shade avoidance responses(SARs)that optimize light absorption but impair plant vigor and performance,limiting yield improvement through increasing plant density.In this study,we demonstrated that high-density-induced leaf angle narrowing and stem/stalk elongation are largely dependent on phytochrome B(phyB1/B2),the primaryphotoreceptor responsible for perceiving red(R)and far-red(FR)light in maize.We found that maize phyB physically interacts with the LIGULELESS1(LG1),a classical key regulator of leaf angle,to coordinately regulate plant architecture and density tolerance.The abundance of LG1 is significantly increased by phyB under high R:FR light(low density)but rapidly decreases under low R:FR light(high density),correlating with variations in leaf angle and plant height under various densities.In addition,we identified the homeobox transcription factor HB53 as a target co-repressed by both phyB and LG1 but rapidly induced by canopy shade.Genetic and cellular analyses showed that HB53 regulates plant architecture by controlling the elongation and division of ligular adaxial and abaxial cells.Taken together,these findings uncover the phyB-LG1-HB53 regulatory module as a key molecular mechanism governing plant architecture and density tolerance,providing potential genetic targets for breeding maize hybrid varieties suitable for high-density planting.

Numerical insight into heat transfer enhancement by granules inner-migration in a moving bed:A performance comparison between slanted-stick and plow-shaped agitator

Waste heat recovery of high-temperature granules is one of the most promising sustainable energy supply and carbon reduction ways for industry.A moving bed indirect heat exchanger(MBIHE)with inner-migration was proposed for granular heat recovery.Granule migration and the enhanced heat transfer induced by two types of agitators(i.e.,agitator with slanted stick A_(s)and with plow-shaped surface A_(p))in the MBIHE are analyzed based on DEM coupled with CFD.Owing to the effective agitation,the average heat transfer coefficient in the granule side is enhanced to∼3 times compared to that without agitation.The heat recovery efficiency in the moving bed reached more than 70%with the agitations of either A_(s)or A_(p).The heat efficiency of A_(s)is∼7%higher than that of A_(p),but with at least 60%greater rotational torque.To ensure reliable agitation,the A_(p)is suggested to be adopted in the MBIHE to induce granule migration.

Correction:Integration of light and hormone signaling pathways in the regulation of plant shade avoidance syndrome

Correction:aBI0TECH(2021)2:131-145 https://doi.0rg/10.1007/s42994-021-00038-1 In this article the author's name Fereshteh Jafari was incorrectly written as Feresheeh Jafari.The original article has been corrected.Open Access This article is licensed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format.

Processing Nomex Nanofibers by Ionic Solution Blow‑Spinning for Efficient High‑Temperature Exhausts Treatment

Hard-to-dissolve polymers provide next-generation alternatives for high-performance filter materials owing to their intrin-sically high chemical stability,superior mechanical performance,and excellent high-temperature resistance.However,the mass production of hard-to-dissolve nanofibers still remains a critical challenge.A simple,scalable,and low-cost ionic solu-tion blow-spinning method has herein been provided for the large-scale preparation of hard-to-dissolve Nomex polymeric nanofibers with an average diameter of nearly 100 nm.After rapidly dissolving Nomex microfibers in the lithium chloride/dimethylacetamide(LiCl/DMAc)solution system,the conductive solution can be stably and conductivity-independently processed into nanofibers.The method optimizes electrospinning and avoids spinnability degradation and potential safety hazards caused by high electrical conductivity.Owing to nanofibrous structure and high dipole moment,Nomex nanofibrous filters show a stable high filtration efficiency of 99.92%for PM_(0.3) with a low areal density of 4.6 g m^(-2),as well as a low-pressure drop of 189.47 Pa.Moreover,the flame-retardant filter can work at 250°C and 280°C for a long and short time without shrinking or burning,respectively,exhibiting a high filtration efficiency of 99.50%for PM_(0.3-10.0).The outstanding properties and low cost enable the efficient capture of PM from various high-temperature exhausts,making Nomex nanofi-brous membrane an even more ideal industrial-grade air filter than polypropylene,polytetrafluoroethylene,polyimide,and ceramic nanofibrous filters.

Double-stretching as an effective and generalizable strategy towards thinner nanofibers in solution blow spinning

Solution blow spinning(SBS)applies high-speed airflow to prepare fibers by generating a strong stretching force.It has the advantages of scalable production,tailorable morphologies,and wide applicability.Yet,the SBS strategy can hardly prepare fibers down to the sub-100 nanometers,which limits its performance in demanding applications.Herein,we overcome the limitation of SBS by introducing a second airflow.This novel strategy is termed double-stretching SBS(DS-SBS)because an extra stretching force is exerted on the fiber when it converges with the second airflow.Polyamide6 nanofibers with an average diameter of 80 nm are successfully prepared with the DS-SBS strategy,while the SBS strategy could only prepare submicron fibers with an average diameter of 120 nm.Further,the generality of the DS-SBS strategy to reduce fiber diameter is verified on numerous solute-solvent pairs.

Gut microbiota:a new insight into neurological diseases

In the last decade,it has become increasingly recognized that a balanced gut microbiota plays an important role in maintaining the health of the host.Numerous clinical and preclinical studies have shown that changes in gut microbiota composition are associated with a variety of neurological diseases,e.g.,Parkinson’s disease,Alzheimer’s disease,and myasthenia gravis.However,the underlying molecular mechanisms are complex and remain unclear.Behavioral phenotypes can be transmitted from humans to animals through gut microbiota transplantation,indicating that the gut microbiota may be an important regulator of neurological diseases.However,further research is required to determine whether animal-based findings can be extended to humans and to elucidate the relevant potential mechanisms by which the gut microbiota regulates neurological diseases.Such investigations may aid in the development of new microbiota-based strategies for diagnosis and treatment and improve the clinical management of neurological disorders.In this review,we describe the dysbiosis of gut microbiota and the corresponding mechanisms in common neurological diseases,and discuss the potential roles that the intestinal microbiome may play in the diagnosis and treatment of neurological disorders.