Bone resorption by osteoclasts is a critical step in bone remodeling,a process important for maintaining bone homeostasis and repairing injured bone.We previously identified a bone marrow mesenchymal subpopulation,mar...Bone resorption by osteoclasts is a critical step in bone remodeling,a process important for maintaining bone homeostasis and repairing injured bone.We previously identified a bone marrow mesenchymal subpopulation,marrow adipogenic lineage precursors(MALPs),and showed that its production of RANKL stimulates bone resorption in young mice using Adipoq-Cre.To exclude developmental defects and to investigate the role of MALPs-derived RANKL in adult bone,we generated inducible reporter mice(Adipoq-CreER Tomato)and RANKL deficient mice(Adipoq-CreER RANKLflox/flox,iCKO).Single cell-RNA sequencing data analysis and lineage tracing revealed that Adipoq+cells contain not only MALPs but also some mesenchymal progenitors capable of osteogenic differentiation.In situ hybridization showed that RANKL mRNA is only detected in MALPs,but not in osteogenic cells.RANKL deficiency in MALPs induced at 3 months of age rapidly increased trabecular bone mass in long bones as well as vertebrae due to diminished bone resorption but had no effect on the cortical bone.Ovariectomy(OVX)induced trabecular bone loss at both sites.RANKL depletion either before OVX or at 6 weeks post OVX protected and restored trabecular bone mass.Furthermore,bone healing after drill-hole injury was delayed in iCKO mice.Together,our findings demonstrate that MALPs play a dominant role in controlling trabecular bone resorption and that RANKL from MALPs is essential for trabecular bone turnover in adult bone homeostasis,postmenopausal bone loss,and injury repair.展开更多
Rockburst precursors are critical for disaster warning,yet the complexity of rockburst has hindered the identification of a unified precursor.Furthermore,the influence of loading rates(LRs)on acoustic emission(AE)prec...Rockburst precursors are critical for disaster warning,yet the complexity of rockburst has hindered the identification of a unified precursor.Furthermore,the influence of loading rates(LRs)on acoustic emission(AE)precursors in different rock types remains poorly understood.This study investigates the AE characteristics and early warning times of rockburst in slate and mica-schist under four LRs(0.05,0.15,0.25,and 0.5 MPa/s)using true triaxial unloading tests.The micro-crack state of the samples was evaluated using entropy,while critical slowing down(CSD)theory was applied to interpret AE precursors.The results reveal that as the LR increases,the rockburst stress of both rocks initially rises and then declines,with mica-schist exhibiting more severe damage and a higher dominance of tensile cracks.Notably,identifying rockburst precursors in mica-schist proved more challenging compared to slate.Among the methods tested,AE amplitude variance outperformed entropy in precursor identification.Additionally,the rockburst early warning time was found to be negatively correlated with the LR,with mica-schist consistently showing shorter warning times than slate.The CSD-derived precursor,due to its enhanced sensitivity,is recommended for early warning systems.These findings provide new insights into the role of LRs in rockburst dynamics and offer practical guidance for improving precursor identification and disaster mitigation strategies.展开更多
Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechani...Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechanical properties of carbon fibers, and therefore affect the overall performance of pultruded composites. This study systematically investigated the influence of PAN precursor properties on the degree of graphitization, surface morphology and mechanical properties of carbon fibers by regulating the molecular weight distribution, stretching ratio and impurity content of PAN precursor, and analyzed the mechanism of action of carbon fiber properties on the interfacial bonding strength and tensile/ bending properties of composites in combination with the pultrusion process. The results showed that when the filament stretchability was increased to 4.5 times, the axial orientation of carbon fibers increased by 18% and the tensile strength reached 520 MPa;Filaments with impurity content below 0.3% increase carbon fiber yield by 5.2% and interlaminar shear strength of composites by 23%. This study provides a theoretical basis for raw material screening and process optimization of high-performance carbon fibers and their composites.展开更多
INTRODUCTION.On May 1st,2024,around 2:10 a.m.,a catastrophic collapse occurred along the Meilong Expressway near Meizhou City,Guangdong Province,China,at coordinates 24°29′24″N and 116°40′25″E.This colla...INTRODUCTION.On May 1st,2024,around 2:10 a.m.,a catastrophic collapse occurred along the Meilong Expressway near Meizhou City,Guangdong Province,China,at coordinates 24°29′24″N and 116°40′25″E.This collapse resulted in a pavement failure of approximately 17.9 m in length and covering an area of about 184.3 m^(2)(Chinanews,2024).展开更多
The increasing sophistication of cyberattacks,coupled with the limitations of rule-based detection systems,underscores the urgent need for proactive and intelligent cybersecurity solutions.Traditional intrusion detect...The increasing sophistication of cyberattacks,coupled with the limitations of rule-based detection systems,underscores the urgent need for proactive and intelligent cybersecurity solutions.Traditional intrusion detection systems often struggle with detecting early-stage threats,particularly in dynamic environments such as IoT,SDNs,and cloud infrastructures.These systems are hindered by high false positive rates,poor adaptability to evolving threats,and reliance on large labeled datasets.To address these challenges,this paper introduces CyberGuard-X,an AI-driven framework designed to identify attack precursors—subtle indicators of malicious intent—before full-scale intrusions occur.CyberGuard-X integrates anomaly detection,time-series analysis,and multi-stage classification within a scalable architecture.The model leverages deep learning techniques such as autoencoders,LSTM networks,and Transformer layers,supported by semi-supervised learning to enhance detection of zero-day and rare threats.Extensive experiments on benchmark datasets(CICIDS2017,CSE-CIC-IDS2018,and UNSW-NB15)demonstrate strong results,including 96.1%accuracy,94.7%precision,and 95.3%recall,while achieving a zero-day detection rate of 84.5%.With an inference time of 12.8 ms and 34.5%latency reduction,the model supports real-time deployment in resource-constrained environments.CyberGuard-X not only surpasses baseline models like LSTM and Random Forest but also enhances proactive threat mitigation across diverse network settings.展开更多
This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic ...This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic response mechanism of coal energy evolution is examined, and the energy instability criterion is established. The validity of the instability criterion is explored from the standpoint of damage progression. The results demonstrate that the energy conversion mechanism undergoes a fundamental alternation under impact disturbance. Moreover, the energy release rate as well as the energy dissipation rate undergo comparable changes across distinct levels of impact disturbance. The distinction between the energy release rate and the energy dissipation rate (DRD) increases as coal mass deformation grows. Prior to coal facing instability and failure, the DRD experienced an inflection point followed by a sharp decrease. In conjunction with the discussion on the damage evolution, the physical and mechanical significance of DRD remains clear, which can essentially describe the whole impact loading process. The phenomenon that the inflection point appears and DRD subsequently suddenly decreases can be employed as the energy criterion prior to the failure of instability. Furthermore, this paper provides significant reference for the prediction of dynamic instability of coal under dynamic disturbance.展开更多
Metal composites produced through the liquid metal dealloying(LMD)process feature an advanced matrix-matrix composite structure,where two metallic materials form a continuous,three-dimensional interconnected network.T...Metal composites produced through the liquid metal dealloying(LMD)process feature an advanced matrix-matrix composite structure,where two metallic materials form a continuous,three-dimensional interconnected network.This study investigates the effects of Ti Cu precursor compositions on dealloying behavior and microstructural evolution in liquid Mg,using Ti_(50)Cu_(50)and Ti_(30)Cu_(70)precursors.The initial microstructure of the precursor significantly influences dealloying kinetics and phase transitions.The single-phase Ti_(50)Cu_(50)precursor exhibits a faster initial dealloying rate due to its homogeneous structure,yet complete dealloying requires 90 min.In contrast,the dualphase Ti_(30)Cu_(70)precursor achieves complete dealloying in 30 min,demonstrating the impact of a higher Cu concentration on accelerating the process kinetics.Additionally,the study explores the coarsening behavior and hardness variations during the LMD process,along with the microstructural characteristics of Mg-Ti composites fabricated from these two precursors.The findings highlight the critical role of precursor composition in tailoring the microstructure and properties of Mg-Ti composites produced through the LMD process,demonstrating its potential for advanced composite material manufacturing.展开更多
The current generation of ultrahigh temperature ceramic precursors typically encounters obstacles in achieving high ceramic yields(<40 wt.%)due to the challenges in integrating significant amounts of boron,which ha...The current generation of ultrahigh temperature ceramic precursors typically encounters obstacles in achieving high ceramic yields(<40 wt.%)due to the challenges in integrating significant amounts of boron,which hampers their conversion into boride-based ultrahigh temperature ceramics.To tackle these challenges,a serious of pioneering liquid multi-component hafnium-containing ceramic SiHfCB precursors(with different Hf/Si ratios)have been developed.These novel precursors are featured with stable molec-ular structure and high ceramic yield which were successfully created through a novel one-pot polymer-ization process.They present in liquid form and their structure is characterized by C-C bonds forming its main chain with branched chains of O-Si-O,Si-O-Hf,Si-O-B,and B-O-Hf which have untapped advantages including uniform component dispersion,and excellent fluidity.The ceramic yield of SiHfCB precursor with Hf/Si of 0.2 is remarkably up to 68.6 wt.%at 1500℃,and their Hf content exceeded 50 wt.%.Of particular interest,the pyrolyzed product HfB_(2)-SiC nanopowders derived from the SiHfCB precursor with Hf/Si of 0.2,consist of nanopowders in the 40-60 nm range with a density of 5.23 g cm^(−3).Remarkably,this material demonstrates exceptional performance in ultrahigh temperature oxygen-containing environ-ments at 2500℃,showing near-zero ablation with a linear ablation rate of just 2.5×10^(−4) mm s^(−1).Post-ablation analysis of the microstructure reveals that the formation of a lava-like HfO_(2) and HfO_(2)-SiO_(2) oxide layer effectively blocks oxygen penetration and provides excellent oxidation resistance.The inno-vative SiHfCB hafnium-containing ceramic precursor offers a groundbreaking solution for the preparation of lightweight ultrahigh-temperature ceramics.This development is poised to provide robust technical support for the use of ultrahigh temperature ceramics in non-ablative thermal protective systems,partic-ularly in the construction of hypersonic vehicles,where ultrahigh temperature resilience is crucial.展开更多
BACKGROUND Differential diagnosis among atypical hyperplasia(AH)(including reparative hyperplasia and intestinal metaplasia),low-grade dysplasia(LGD),high-grade dysplasia(HGD),and adenocarcinoma(AC)in gastric mucosal ...BACKGROUND Differential diagnosis among atypical hyperplasia(AH)(including reparative hyperplasia and intestinal metaplasia),low-grade dysplasia(LGD),high-grade dysplasia(HGD),and adenocarcinoma(AC)in gastric mucosal biopsies is challenging due to histomorphological overlaps,variability in pathological diagnosis consistency,and limited reproducibility.AIM To evaluate the diagnostic utility of P53,Ki67,P504S,and IMP3 in gastric cancer and its precancerous lesions,focusing on their effectiveness in distinguishing AH,LGD,HGD,and AC.METHODS From January 2018 to September 2020,a total of 185 gastric mucosal biopsy specimens were analyzed according to the pathological diagnostic criteria outlined in the World Health Organization Classification of Digestive System Tumors(2019).The specimens were categorized into four groups:AH,LGD,HGD,and AC.Immunohistochemistry was employed to assess the expression status of P53,Ki67,P504S,and IMP3.Intergroup comparisons were performed using theχ^(2)test or Fisher's exact probability test to compare the differences in immunohistochemical markers across the distinct lesion groups.RESULTS The expression rate of P504S was highest in the LGD group(53.3%,16/30),while IMP3 expression was highest in the AC group(41.9%,26/62),followed by the HGD group(33.3%).Significant differences in P504S and IMP3 expression levels were observed among the four lesion groups(P<0.001).Pairwise comparisons revealed statistically significant differences in P504S expression between the AH group and the LGD,HGD,and AC groups(P<0.001),as well as significant variations in IMP3 expression between the AH group and the HGD and AC groups,and between the LGD group and the HGD and AC groups(P<0.001).Additionally,significant correlations were found between P504S and the polarity expression pattern of Ki67,and between IMP3 and the mutation expression pattern of P53(P<0.001).The combined detection of P504S with Ki67 and IMP3 with P53 increased the diagnostic sensitivity for LGD and HGD/AC,respectively.CONCLUSION P504S is highly expressed in LGD and is associated with the Ki67“polarity”expression pattern.IMP3 is highly expressed in HGD/AC and is correlated with the P53 mutation expression pattern.The combined detection of P504S with Ki67 and IMP3 with P53 increased the diagnostic sensitivity for LGD and HGD/AC,respectively.The rational use of P504S,Ki67,IMP3,and p53 can help distinguish gastric cancer and precancerous lesions,improving the early cancer diagnosis rate.展开更多
Objective To reveal the effects and potential mechanisms by which synaptic vesicle glycoprotein 2A(SV2A)influences the distribution of amyloid precursor protein(APP)in the trans-Golgi network(TGN),endolysosomal system...Objective To reveal the effects and potential mechanisms by which synaptic vesicle glycoprotein 2A(SV2A)influences the distribution of amyloid precursor protein(APP)in the trans-Golgi network(TGN),endolysosomal system,and cell membranes and to reveal the effects of SV2A on APP amyloid degradation.Methods Colocalization analysis of APP with specific tagged proteins in the TGN,ensolysosomal system,and cell membrane was performed to explore the effects of SV2A on the intracellular transport of APP.APP,β-site amyloid precursor protein cleaving enzyme 1(BACE1)expressions,and APP cleavage products levels were investigated to observe the effects of SV2A on APP amyloidogenic processing.Results APP localization was reduced in the TGN,early endosomes,late endosomes,and lysosomes,whereas it was increased in the recycling endosomes and cell membrane of SV2A-overexpressed neurons.Moreover,Arl5b(ADP-ribosylation factor 5b),a protein responsible for transporting APP from the TGN to early endosomes,was upregulated by SV2A.SV2A overexpression also decreased APP transport from the cell membrane to early endosomes by downregulating APP endocytosis.In addition,products of APP amyloid degradation,including sAPPβ,Aβ1-42,and Aβ1-40,were decreased in SV2A-overexpressed cells.Conclusion These results demonstrated that SV2A promotes APP transport from the TGN to early endosomes by upregulating Arl5b and promoting APP transport from early endosomes to recycling endosomes-cell membrane pathway,which slows APP amyloid degradation.展开更多
Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection...Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection applications.Additionally,their commendable secondary processing characteristics enable the development of diverse composite materials when integrated with other materials,significantly broadening the potential utilization of ThO_(2)materials and thorium resources in industrial fields.In this work,the ThO_(2)fiber was fabricated by the sol-gel precursor method,and the precursor with good spinnability and excellent stability was synthesized for the first time.The ThO_(2)fiber with a mean diameter of 868 nm is both highly flexible and strong(max.tensile strength 2.21 MPa),capable of bending freely across a wide temperature range from-196℃(in liquid nitrogen)to 1200℃.Meanwhile,it exhibits excellent temperature stability and heat insulation properties.The ThO_(2)nanofiber membranes with layered structure have low density(32-37 mg·cm^(-3)),low thermal conductivity(27.3-30.1 mW·m^(-1)·K^(-1)@25℃).The ThO_(2)nanofiber membranes with 15 mm thickness can reduce the temperature from 1200 to 282℃and maintain a high aspect ratio and bendability after 1200℃@90 min.The results show that the ThO_(2)fiber can be used as a new kind of high-temperature resistant material.展开更多
Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model,experimental autoimmune encephalomyelitis(EAE).This study investigates the...Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model,experimental autoimmune encephalomyelitis(EAE).This study investigates the role of high mobility group box 1(HMGB1)in oligodendrocyte precursor cells(OPCs)in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier(BBB)by using OPC-specific HMGB1 knockout(KO)mice.We found that HMGB1 released from OPCs promotes BBB disruption,subsequently allowing increased immune cell infiltration.The migration of CD4+T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes(OLs).OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS,leading to less damage to the myelin sheath and mitigated EAE progression.CD4+T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs.Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.展开更多
To develop a melting-based larger-scale fabrication process for oxide dispersion strengthened(ODS)steel,this study proposed a method of zone melting with built-in precursor powder(ZMPP),followed by hot forging and agi...To develop a melting-based larger-scale fabrication process for oxide dispersion strengthened(ODS)steel,this study proposed a method of zone melting with built-in precursor powder(ZMPP),followed by hot forging and aging treatments.A 50 kg ingot was successfully prepared,highlighting the scalability of this innovative process.Microstructural analysis revealed a predominantly lath martensite matrix with a small amount of ferrite in the hot-forged ODS steel,without oxide particle aggregation.Aging at 750℃ resulted in the formation of sub-micron-sized Cr_(23)C_(6) particles at grain boundaries and martensitic lath interfaces,accompanied by a high-density(7.64×1023 m^(-3))nano-scale(~6 nm)Y-Si-O complex oxides after 25 h.Additionally,the hot-forged sample exhibited a high yield strength(871 MPa)but limited ductility(5.0%).Aging treatments led to an increase in ductility but a decrease in yield strength.Notably,prolonged aging maintained the strength level of steels while enhancing ductility,with a 23.3% total elongation observed after 25 h.The novel ZMPP method,preparing high-quality ODS steels with uniform microstructure and good mechanical properties,provided a new avenue for large-scale production of ODS steels.展开更多
Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β...Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β-Ga_(2)O_(3) MOS capacitors were fabricated with ALD deposited Al_(2)O_(3) using H_(2)O or ozone(O_(3)) as precursors. Compared with the Al_(2)O_(3) gate dielectric with H_(2)O as ALD precursor, the leakage current for the O_(3) precursor case is decreased by two orders of magnitude, while it keeps the same level at the fixed charges, interface state density, and border traps. The SIMS tests show that Al_(2)O_(3) with O_(3) as precursor contains more carbon impurities. The current transport mechanism analysis suggests that the C–H complex in Al_(2)O_(3) with O_(3) precursor serves as deep energy trap to reduce the leakage current. These results indicate that the Al_(2)O_(3)/β-Ga_(2)O_(3)MOS capacitor using the O_(3) precursor has a low leakage current and holds potential for application in β-Ga_(2)O_(3) MOSFETs.展开更多
The method for precursor information acquisition based on acoustic emission(AE)data for jointed rock masses is of significant importance for the early warning of dynamic disasters in underground engineering.A clusteri...The method for precursor information acquisition based on acoustic emission(AE)data for jointed rock masses is of significant importance for the early warning of dynamic disasters in underground engineering.A clustering-convolutional neural network(CNN)method is proposed,which comprises a clustering component and a CNN component.A series of uniaxial compression tests were conducted on granite specimens containing a persistent sawtooth joint,with different strain rates(105e102 s1)and joint inclination angles(0e50).The results demonstrate that traditional precursory indicators based on full waveforms are effective for obtaining precursor information of the intact rock failure.However,these indicators are not universally applicable to the failure of rock masses with a single joint.The clustering-CNN method has the potential to be applied to obtain precursor information for all three failure modes(Modes I,II and III).Following the waveform clustering analysis,the effective waveforms exhibit a low main frequency,as well as high energy,ringing count,and rise time.Furthermore,the clustering method and the precursory indicators influence the acquisition of final precursor information.The Birch hierarchical clustering method and the S value precursory indicator can help to obtain more accurate results.The findings of this study may contribute to the development of warning methods for underground engineering across faults.展开更多
Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as ...Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.展开更多
To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system...To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real time.The experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial depth.And then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of rockburst.What’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack evolution.Finally,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor.展开更多
The efficient and environmentally friendly recycling technology of waste residue that including abundant heavy metal produced during the recovery of lithium batteries has become a research hotspot.Herein,a novelty pro...The efficient and environmentally friendly recycling technology of waste residue that including abundant heavy metal produced during the recovery of lithium batteries has become a research hotspot.Herein,a novelty process of acid leaching-selective electrodeposition-deep impurity removal-regeneration was proposed to recovery of the CuS slag,which has been efficient transferred to high purity cathode copper and commercially available ternary precursors.Copper cathode with a purity of 99.67%was prepared under electrochemical reaction conditions at-0.55 V for 2 h.A novel impurity remover-Mn powder,which was used to remove the residual impurities and as a feedstock for the ternary precursor.Finally,NCM523 was regenerated by co-precipitation.The process is superior to the traditional process in economy,energy consumption,CO_(2)emissions,product purity and process duration.This study provides a new approach for solid waste recovery and precious metal enrichment.展开更多
The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibite...The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.展开更多
Oligodendrocyte precursor cells(OPCs)are a heterogeneous multipotent population in the central nervous system(CNS)that appear during embryogenesis and persist as resident cells in the adult brain parenchyma.OPCs could...Oligodendrocyte precursor cells(OPCs)are a heterogeneous multipotent population in the central nervous system(CNS)that appear during embryogenesis and persist as resident cells in the adult brain parenchyma.OPCs could generate oligodendrocytes to participate in myelination.Recent advances have renewed our knowledge of OPC biology by discovering novel markers of oligodendroglial cells,the myelin-independent roles of OPCs,and the regulatory mechanism of OPC development.In this review,we will explore the updated knowledge on OPC identity,their multifaceted roles in the CNS in health and diseases,as well as the regulatory mechanisms that are involved in their developmental stages,which hopefully would contribute to a further understanding of OPCs and attract attention in the field of OPC biology.展开更多
基金supported by NIH grants NIH/NIA R01AG069401(to L.Q.)NIH/NHLBI U54HL165442(to K.T.)P30AR069619(to Penn Center for Musculoskeletal Disorders).
文摘Bone resorption by osteoclasts is a critical step in bone remodeling,a process important for maintaining bone homeostasis and repairing injured bone.We previously identified a bone marrow mesenchymal subpopulation,marrow adipogenic lineage precursors(MALPs),and showed that its production of RANKL stimulates bone resorption in young mice using Adipoq-Cre.To exclude developmental defects and to investigate the role of MALPs-derived RANKL in adult bone,we generated inducible reporter mice(Adipoq-CreER Tomato)and RANKL deficient mice(Adipoq-CreER RANKLflox/flox,iCKO).Single cell-RNA sequencing data analysis and lineage tracing revealed that Adipoq+cells contain not only MALPs but also some mesenchymal progenitors capable of osteogenic differentiation.In situ hybridization showed that RANKL mRNA is only detected in MALPs,but not in osteogenic cells.RANKL deficiency in MALPs induced at 3 months of age rapidly increased trabecular bone mass in long bones as well as vertebrae due to diminished bone resorption but had no effect on the cortical bone.Ovariectomy(OVX)induced trabecular bone loss at both sites.RANKL depletion either before OVX or at 6 weeks post OVX protected and restored trabecular bone mass.Furthermore,bone healing after drill-hole injury was delayed in iCKO mice.Together,our findings demonstrate that MALPs play a dominant role in controlling trabecular bone resorption and that RANKL from MALPs is essential for trabecular bone turnover in adult bone homeostasis,postmenopausal bone loss,and injury repair.
基金supported by the National Natural Science Foundation of China(Nos.52374119,42477142 and 42277154)Natural Science Foundation of Jiangsu Province(No.BK20242059)+1 种基金the open fund of State Key Laboratory of Hydraulics and Mountain River Engineering(No.SKHL2306)the High-level Talent Introduction Project of Changzhou University(No.ZMF24020037)。
文摘Rockburst precursors are critical for disaster warning,yet the complexity of rockburst has hindered the identification of a unified precursor.Furthermore,the influence of loading rates(LRs)on acoustic emission(AE)precursors in different rock types remains poorly understood.This study investigates the AE characteristics and early warning times of rockburst in slate and mica-schist under four LRs(0.05,0.15,0.25,and 0.5 MPa/s)using true triaxial unloading tests.The micro-crack state of the samples was evaluated using entropy,while critical slowing down(CSD)theory was applied to interpret AE precursors.The results reveal that as the LR increases,the rockburst stress of both rocks initially rises and then declines,with mica-schist exhibiting more severe damage and a higher dominance of tensile cracks.Notably,identifying rockburst precursors in mica-schist proved more challenging compared to slate.Among the methods tested,AE amplitude variance outperformed entropy in precursor identification.Additionally,the rockburst early warning time was found to be negatively correlated with the LR,with mica-schist consistently showing shorter warning times than slate.The CSD-derived precursor,due to its enhanced sensitivity,is recommended for early warning systems.These findings provide new insights into the role of LRs in rockburst dynamics and offer practical guidance for improving precursor identification and disaster mitigation strategies.
文摘Polyacrylonitrile (PAN) precursor is a core precursor for the preparation of high-performance carbon fibers. Its unique chemical structure and physical properties directly contributes to the microstructure and mechanical properties of carbon fibers, and therefore affect the overall performance of pultruded composites. This study systematically investigated the influence of PAN precursor properties on the degree of graphitization, surface morphology and mechanical properties of carbon fibers by regulating the molecular weight distribution, stretching ratio and impurity content of PAN precursor, and analyzed the mechanism of action of carbon fiber properties on the interfacial bonding strength and tensile/ bending properties of composites in combination with the pultrusion process. The results showed that when the filament stretchability was increased to 4.5 times, the axial orientation of carbon fibers increased by 18% and the tensile strength reached 520 MPa;Filaments with impurity content below 0.3% increase carbon fiber yield by 5.2% and interlaminar shear strength of composites by 23%. This study provides a theoretical basis for raw material screening and process optimization of high-performance carbon fibers and their composites.
基金supported by the National Natural Science Foundation of China(Nos.42371094,41907253)partially supported by the Interdisciplinary Cultivation Program of Xidian University(No.21103240005)the Postdoctoral Fellowship Program of CPSF(No.GZB20240589)。
文摘INTRODUCTION.On May 1st,2024,around 2:10 a.m.,a catastrophic collapse occurred along the Meilong Expressway near Meizhou City,Guangdong Province,China,at coordinates 24°29′24″N and 116°40′25″E.This collapse resulted in a pavement failure of approximately 17.9 m in length and covering an area of about 184.3 m^(2)(Chinanews,2024).
文摘The increasing sophistication of cyberattacks,coupled with the limitations of rule-based detection systems,underscores the urgent need for proactive and intelligent cybersecurity solutions.Traditional intrusion detection systems often struggle with detecting early-stage threats,particularly in dynamic environments such as IoT,SDNs,and cloud infrastructures.These systems are hindered by high false positive rates,poor adaptability to evolving threats,and reliance on large labeled datasets.To address these challenges,this paper introduces CyberGuard-X,an AI-driven framework designed to identify attack precursors—subtle indicators of malicious intent—before full-scale intrusions occur.CyberGuard-X integrates anomaly detection,time-series analysis,and multi-stage classification within a scalable architecture.The model leverages deep learning techniques such as autoencoders,LSTM networks,and Transformer layers,supported by semi-supervised learning to enhance detection of zero-day and rare threats.Extensive experiments on benchmark datasets(CICIDS2017,CSE-CIC-IDS2018,and UNSW-NB15)demonstrate strong results,including 96.1%accuracy,94.7%precision,and 95.3%recall,while achieving a zero-day detection rate of 84.5%.With an inference time of 12.8 ms and 34.5%latency reduction,the model supports real-time deployment in resource-constrained environments.CyberGuard-X not only surpasses baseline models like LSTM and Random Forest but also enhances proactive threat mitigation across diverse network settings.
基金Projects(51934007,12072363,52004268) supported by the National Natural Science Foundation of ChinaProject(22KJD440002) supported by the Natural Science Fund for Colleges and Universities in Jiangsu Province,China。
文摘This study investigates the instability characteristics of dynamic disasters resulting from disruption caused by extracting resources underground. Utilizing the split Hopkinson pressure bar (SHPB) system, the dynamic response mechanism of coal energy evolution is examined, and the energy instability criterion is established. The validity of the instability criterion is explored from the standpoint of damage progression. The results demonstrate that the energy conversion mechanism undergoes a fundamental alternation under impact disturbance. Moreover, the energy release rate as well as the energy dissipation rate undergo comparable changes across distinct levels of impact disturbance. The distinction between the energy release rate and the energy dissipation rate (DRD) increases as coal mass deformation grows. Prior to coal facing instability and failure, the DRD experienced an inflection point followed by a sharp decrease. In conjunction with the discussion on the damage evolution, the physical and mechanical significance of DRD remains clear, which can essentially describe the whole impact loading process. The phenomenon that the inflection point appears and DRD subsequently suddenly decreases can be employed as the energy criterion prior to the failure of instability. Furthermore, this paper provides significant reference for the prediction of dynamic instability of coal under dynamic disturbance.
基金supported by the National Research Foundation of Korea(NRF)grants funded by the Korea government(MSIT)(Nos.RS-2024–00351052 and RS-2024–00450561)。
文摘Metal composites produced through the liquid metal dealloying(LMD)process feature an advanced matrix-matrix composite structure,where two metallic materials form a continuous,three-dimensional interconnected network.This study investigates the effects of Ti Cu precursor compositions on dealloying behavior and microstructural evolution in liquid Mg,using Ti_(50)Cu_(50)and Ti_(30)Cu_(70)precursors.The initial microstructure of the precursor significantly influences dealloying kinetics and phase transitions.The single-phase Ti_(50)Cu_(50)precursor exhibits a faster initial dealloying rate due to its homogeneous structure,yet complete dealloying requires 90 min.In contrast,the dualphase Ti_(30)Cu_(70)precursor achieves complete dealloying in 30 min,demonstrating the impact of a higher Cu concentration on accelerating the process kinetics.Additionally,the study explores the coarsening behavior and hardness variations during the LMD process,along with the microstructural characteristics of Mg-Ti composites fabricated from these two precursors.The findings highlight the critical role of precursor composition in tailoring the microstructure and properties of Mg-Ti composites produced through the LMD process,demonstrating its potential for advanced composite material manufacturing.
基金supported by the Key Program of the National Natural Science Foundation of China(No.52032003)the Major Program of the National Natural Science Foundation of China(No.52293372)+2 种基金the National Natural Science Foundation of China(No.51972082)the National Natural Science Foundation of China(No.52102093)the National Natural Science Foundation of China(No.52172041)and the science foundation of national key laboratory of science and technology on advanced composites in special environments.
文摘The current generation of ultrahigh temperature ceramic precursors typically encounters obstacles in achieving high ceramic yields(<40 wt.%)due to the challenges in integrating significant amounts of boron,which hampers their conversion into boride-based ultrahigh temperature ceramics.To tackle these challenges,a serious of pioneering liquid multi-component hafnium-containing ceramic SiHfCB precursors(with different Hf/Si ratios)have been developed.These novel precursors are featured with stable molec-ular structure and high ceramic yield which were successfully created through a novel one-pot polymer-ization process.They present in liquid form and their structure is characterized by C-C bonds forming its main chain with branched chains of O-Si-O,Si-O-Hf,Si-O-B,and B-O-Hf which have untapped advantages including uniform component dispersion,and excellent fluidity.The ceramic yield of SiHfCB precursor with Hf/Si of 0.2 is remarkably up to 68.6 wt.%at 1500℃,and their Hf content exceeded 50 wt.%.Of particular interest,the pyrolyzed product HfB_(2)-SiC nanopowders derived from the SiHfCB precursor with Hf/Si of 0.2,consist of nanopowders in the 40-60 nm range with a density of 5.23 g cm^(−3).Remarkably,this material demonstrates exceptional performance in ultrahigh temperature oxygen-containing environ-ments at 2500℃,showing near-zero ablation with a linear ablation rate of just 2.5×10^(−4) mm s^(−1).Post-ablation analysis of the microstructure reveals that the formation of a lava-like HfO_(2) and HfO_(2)-SiO_(2) oxide layer effectively blocks oxygen penetration and provides excellent oxidation resistance.The inno-vative SiHfCB hafnium-containing ceramic precursor offers a groundbreaking solution for the preparation of lightweight ultrahigh-temperature ceramics.This development is poised to provide robust technical support for the use of ultrahigh temperature ceramics in non-ablative thermal protective systems,partic-ularly in the construction of hypersonic vehicles,where ultrahigh temperature resilience is crucial.
基金Supported by The Science and Technology Research Project of Anyang,No.2022C01SF074。
文摘BACKGROUND Differential diagnosis among atypical hyperplasia(AH)(including reparative hyperplasia and intestinal metaplasia),low-grade dysplasia(LGD),high-grade dysplasia(HGD),and adenocarcinoma(AC)in gastric mucosal biopsies is challenging due to histomorphological overlaps,variability in pathological diagnosis consistency,and limited reproducibility.AIM To evaluate the diagnostic utility of P53,Ki67,P504S,and IMP3 in gastric cancer and its precancerous lesions,focusing on their effectiveness in distinguishing AH,LGD,HGD,and AC.METHODS From January 2018 to September 2020,a total of 185 gastric mucosal biopsy specimens were analyzed according to the pathological diagnostic criteria outlined in the World Health Organization Classification of Digestive System Tumors(2019).The specimens were categorized into four groups:AH,LGD,HGD,and AC.Immunohistochemistry was employed to assess the expression status of P53,Ki67,P504S,and IMP3.Intergroup comparisons were performed using theχ^(2)test or Fisher's exact probability test to compare the differences in immunohistochemical markers across the distinct lesion groups.RESULTS The expression rate of P504S was highest in the LGD group(53.3%,16/30),while IMP3 expression was highest in the AC group(41.9%,26/62),followed by the HGD group(33.3%).Significant differences in P504S and IMP3 expression levels were observed among the four lesion groups(P<0.001).Pairwise comparisons revealed statistically significant differences in P504S expression between the AH group and the LGD,HGD,and AC groups(P<0.001),as well as significant variations in IMP3 expression between the AH group and the HGD and AC groups,and between the LGD group and the HGD and AC groups(P<0.001).Additionally,significant correlations were found between P504S and the polarity expression pattern of Ki67,and between IMP3 and the mutation expression pattern of P53(P<0.001).The combined detection of P504S with Ki67 and IMP3 with P53 increased the diagnostic sensitivity for LGD and HGD/AC,respectively.CONCLUSION P504S is highly expressed in LGD and is associated with the Ki67“polarity”expression pattern.IMP3 is highly expressed in HGD/AC and is correlated with the P53 mutation expression pattern.The combined detection of P504S with Ki67 and IMP3 with P53 increased the diagnostic sensitivity for LGD and HGD/AC,respectively.The rational use of P504S,Ki67,IMP3,and p53 can help distinguish gastric cancer and precancerous lesions,improving the early cancer diagnosis rate.
基金supported by grants from the State Key Program of the National Natural Science Foundation of China(grant number 82030064)Beijing Hospital Authority Youth Program(grant number QML20230812)+2 种基金Research and Development Foundation of Capital Medical University(grant number PYZ23052)National Natural Science Youth Cultivation Project of Xuanwu Hospital,Capital Medical University(grant number QNPY202317)Capital Medical University Research and Cultivation Fund(grant number PYZ23049).
文摘Objective To reveal the effects and potential mechanisms by which synaptic vesicle glycoprotein 2A(SV2A)influences the distribution of amyloid precursor protein(APP)in the trans-Golgi network(TGN),endolysosomal system,and cell membranes and to reveal the effects of SV2A on APP amyloid degradation.Methods Colocalization analysis of APP with specific tagged proteins in the TGN,ensolysosomal system,and cell membrane was performed to explore the effects of SV2A on the intracellular transport of APP.APP,β-site amyloid precursor protein cleaving enzyme 1(BACE1)expressions,and APP cleavage products levels were investigated to observe the effects of SV2A on APP amyloidogenic processing.Results APP localization was reduced in the TGN,early endosomes,late endosomes,and lysosomes,whereas it was increased in the recycling endosomes and cell membrane of SV2A-overexpressed neurons.Moreover,Arl5b(ADP-ribosylation factor 5b),a protein responsible for transporting APP from the TGN to early endosomes,was upregulated by SV2A.SV2A overexpression also decreased APP transport from the cell membrane to early endosomes by downregulating APP endocytosis.In addition,products of APP amyloid degradation,including sAPPβ,Aβ1-42,and Aβ1-40,were decreased in SV2A-overexpressed cells.Conclusion These results demonstrated that SV2A promotes APP transport from the TGN to early endosomes by upregulating Arl5b and promoting APP transport from early endosomes to recycling endosomes-cell membrane pathway,which slows APP amyloid degradation.
基金supported by the National Natural Science Foundation of China(No.52202090)the Fundamental Research Funds for the Central Universities(No.2082019014).
文摘Thorium dioxide(ThO_(2))fibers exhibit exceptional structural stability,low density and superior flexibility,coupled with a remarkably high melting point,positioning them as promising candidates for thermal protection applications.Additionally,their commendable secondary processing characteristics enable the development of diverse composite materials when integrated with other materials,significantly broadening the potential utilization of ThO_(2)materials and thorium resources in industrial fields.In this work,the ThO_(2)fiber was fabricated by the sol-gel precursor method,and the precursor with good spinnability and excellent stability was synthesized for the first time.The ThO_(2)fiber with a mean diameter of 868 nm is both highly flexible and strong(max.tensile strength 2.21 MPa),capable of bending freely across a wide temperature range from-196℃(in liquid nitrogen)to 1200℃.Meanwhile,it exhibits excellent temperature stability and heat insulation properties.The ThO_(2)nanofiber membranes with layered structure have low density(32-37 mg·cm^(-3)),low thermal conductivity(27.3-30.1 mW·m^(-1)·K^(-1)@25℃).The ThO_(2)nanofiber membranes with 15 mm thickness can reduce the temperature from 1200 to 282℃and maintain a high aspect ratio and bendability after 1200℃@90 min.The results show that the ThO_(2)fiber can be used as a new kind of high-temperature resistant material.
基金supported by the National Research Foundation of Korea(NRF)funded by the government of the Republic of Korea[2023R1A2C1004955]the Technology Innovation Program funded by the Ministry of Trade,Industry&Energy(Korea)(20009707)+1 种基金the Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(2020R1A6A3A01099056)the Korea Institute for Advancement of Technology funded by the Ministry of Trade,Industry and Energy(P0025489).
文摘Infiltration and activation of peripheral immune cells are critical in the progression of multiple sclerosis and its experimental animal model,experimental autoimmune encephalomyelitis(EAE).This study investigates the role of high mobility group box 1(HMGB1)in oligodendrocyte precursor cells(OPCs)in modulating pathogenic T cells infiltrating the central nervous system through the blood-brain barrier(BBB)by using OPC-specific HMGB1 knockout(KO)mice.We found that HMGB1 released from OPCs promotes BBB disruption,subsequently allowing increased immune cell infiltration.The migration of CD4+T cells isolated from EAE-induced mice was enhanced when co-cultured with OPCs compared to oligodendrocytes(OLs).OPC-specific HMGB1 KO mice exhibited lower BBB permeability and reduced immune cell infiltration into the CNS,leading to less damage to the myelin sheath and mitigated EAE progression.CD4+T cell migration was also reduced when co-cultured with HMGB1 knock-out OPCs.Our findings reveal that HMGB1 secretion from OPCs is crucial for regulating immune cell infiltration and provides insights into the immunomodulatory function of OPCs in autoimmune diseases.
基金financially supported by the National Natural Science Foundation of China(Nos.52271034,52301058 and 52471042)the National MCF Energy R&D Program of China(No.2018YFE0306102)+1 种基金the China Postdoctoral Science Foundation(No.2023M732183)the Postdoctoral Fellowship Program of CPSF(No.GZB20230399).
文摘To develop a melting-based larger-scale fabrication process for oxide dispersion strengthened(ODS)steel,this study proposed a method of zone melting with built-in precursor powder(ZMPP),followed by hot forging and aging treatments.A 50 kg ingot was successfully prepared,highlighting the scalability of this innovative process.Microstructural analysis revealed a predominantly lath martensite matrix with a small amount of ferrite in the hot-forged ODS steel,without oxide particle aggregation.Aging at 750℃ resulted in the formation of sub-micron-sized Cr_(23)C_(6) particles at grain boundaries and martensitic lath interfaces,accompanied by a high-density(7.64×1023 m^(-3))nano-scale(~6 nm)Y-Si-O complex oxides after 25 h.Additionally,the hot-forged sample exhibited a high yield strength(871 MPa)but limited ductility(5.0%).Aging treatments led to an increase in ductility but a decrease in yield strength.Notably,prolonged aging maintained the strength level of steels while enhancing ductility,with a 23.3% total elongation observed after 25 h.The novel ZMPP method,preparing high-quality ODS steels with uniform microstructure and good mechanical properties,provided a new avenue for large-scale production of ODS steels.
基金Project supported in part by the Science and Technology Development Plan Project of Jilin Province, China (Grant No. YDZJ202303CGZH022)the National Key Research and Development Program of China (Grant No. 2024YFE0205300)+1 种基金the National Natural Science Foundation of China (Grant No. 62471504)the Open Fund of the State Key Laboratory of Optoelectronic Materials and Technologies (Sun Yat-Sen University) (Grant No. OEMT-2023KF-05)。
文摘Metal–insulator–semiconductor(MOS) capacitor is a key structure for high performance MOS field transistors(MOSFETs), requiring low leakage current, high breakdown voltage, and low interface states. In this paper, β-Ga_(2)O_(3) MOS capacitors were fabricated with ALD deposited Al_(2)O_(3) using H_(2)O or ozone(O_(3)) as precursors. Compared with the Al_(2)O_(3) gate dielectric with H_(2)O as ALD precursor, the leakage current for the O_(3) precursor case is decreased by two orders of magnitude, while it keeps the same level at the fixed charges, interface state density, and border traps. The SIMS tests show that Al_(2)O_(3) with O_(3) as precursor contains more carbon impurities. The current transport mechanism analysis suggests that the C–H complex in Al_(2)O_(3) with O_(3) precursor serves as deep energy trap to reduce the leakage current. These results indicate that the Al_(2)O_(3)/β-Ga_(2)O_(3)MOS capacitor using the O_(3) precursor has a low leakage current and holds potential for application in β-Ga_(2)O_(3) MOSFETs.
基金support from the National Natural Science Foundation of China(Grant Nos.52079134 and 51991393).
文摘The method for precursor information acquisition based on acoustic emission(AE)data for jointed rock masses is of significant importance for the early warning of dynamic disasters in underground engineering.A clustering-convolutional neural network(CNN)method is proposed,which comprises a clustering component and a CNN component.A series of uniaxial compression tests were conducted on granite specimens containing a persistent sawtooth joint,with different strain rates(105e102 s1)and joint inclination angles(0e50).The results demonstrate that traditional precursory indicators based on full waveforms are effective for obtaining precursor information of the intact rock failure.However,these indicators are not universally applicable to the failure of rock masses with a single joint.The clustering-CNN method has the potential to be applied to obtain precursor information for all three failure modes(Modes I,II and III).Following the waveform clustering analysis,the effective waveforms exhibit a low main frequency,as well as high energy,ringing count,and rise time.Furthermore,the clustering method and the precursory indicators influence the acquisition of final precursor information.The Birch hierarchical clustering method and the S value precursory indicator can help to obtain more accurate results.The findings of this study may contribute to the development of warning methods for underground engineering across faults.
基金supported by the National Natural Science Foundation of China(52325001,52170009,and 52091542)the National Key Research and Development Program of China(2021YFC3200700)+3 种基金the Program of Shanghai Academic Research Leader,China(21XD1424000)the International Cooperation Project of Shanghai Science and Technology Commission(20230714100)the Key-Area Research and Development Program of Guangdong Province(2020B1111350001)Tongji University Youth 100 Program.
文摘Tracing the contamination origins in water sources and identifying the impacts of natural and human processes are essential for ecological safety and public health.However,current analysis approaches are not ideal,as they tend to be laborious,time-consuming,or technically difficult.Disinfection byproducts(DBPs)are a family of well-known secondary pollutants formed by the reactions of chemical disinfectants with DBP precursors during water disinfection treatment.Since DBP precursors have various origins(e.g.,natural,domestic,industrial,and agricultural sources),and since the formation of DBPs from different precursors in the presence of specific disinfectants is distinctive,we argue that DBPs and DBP precursors can serve as alternative indicators to assess the contamination in water sources and identify pollution origins.After providing a retrospective of the origins of DBPs and DBP precursors,as well as the specific formation patterns of DBPs from different precursors,this article presents an overview of the impacts of various natural and anthropogenic factors on DBPs and DBP precursors in drinking water sources.In practice,the DBPs(i.e.,their concentration and speciation)originally present in source water and the DBP precursors determined using DBP formation potential tests—in which water samples are dosed with a stoichiometric excess of specific disinfectants in order to maximize DBP formation under certain reaction conditions—can be considered as alternative metrics.When jointly used with other water quality parameters(e.g.,dissolved organic carbon,dissolved organic nitrogen,fluorescence,and molecular weight distribution)and specific contaminants of emerging concern(e.g.,certain pharmaceuticals and personal care products),DBPs and DBP precursors in drinking water sources can provide a more comprehensive picture of water pollution for better managing water resources and ensuring human health.
基金support from the National Natural Science Foundation of China(No.41941018,No.52074299)the Fundamental Research Funds for the Central Universities(No.2023JCCXSB02)the China Geological Survey Project(DD20221816,DD20211376)are gratefully acknowledged.
文摘To investigate the influence mechanism of geostress on rockburst characteristics,three groups of gneiss rockburst experiments were conducted under different initial geostress conditions.A high-speed photography system and acoustic emission(AE)monitoring system were used to monitor the entire rockburst process in real time.The experimental results show that when the initial burial depth increases from 928 m to 1320 m,the proportion of large fracture scale in rockburst increases by 154.54%,and the AE energy increases by 565.63%,reflecting that the degree and severity of rockburst increase with the increase of burial depth.And then,two mechanisms are proposed to explain this effect,including(i)the increase of initial geostress improves the energy storage capacity of gneiss,and then,the excess energy which can be converted into kinetic energy of debris ejection increases,consequently,a more pronounced violent ejection phenomenon is observed at rockburst;(ii)the increase of initial geostress causes more sufficient plate cracks of gneiss after unloading ofσh,which provides a basis for more severe ejection of rockburst.What’s more,a precursor with clear physical meaning for rockburst is proposed under the framework of dynamic response process of crack evolution.Finally,potential value in long term rockburst warning of the precursor obtained in this study is shown via the comparison of conventional precursor.
基金financially supported by the Key Project of Research and Development Plan of Jiangxi Province(Nos.20223BBG74006 and 20201BBE51007)the National Science Foundation of China(No.52060018)the National Science Fund for Distinguished Young Scholars(No.52125002)。
文摘The efficient and environmentally friendly recycling technology of waste residue that including abundant heavy metal produced during the recovery of lithium batteries has become a research hotspot.Herein,a novelty process of acid leaching-selective electrodeposition-deep impurity removal-regeneration was proposed to recovery of the CuS slag,which has been efficient transferred to high purity cathode copper and commercially available ternary precursors.Copper cathode with a purity of 99.67%was prepared under electrochemical reaction conditions at-0.55 V for 2 h.A novel impurity remover-Mn powder,which was used to remove the residual impurities and as a feedstock for the ternary precursor.Finally,NCM523 was regenerated by co-precipitation.The process is superior to the traditional process in economy,energy consumption,CO_(2)emissions,product purity and process duration.This study provides a new approach for solid waste recovery and precious metal enrichment.
文摘The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.
基金supported by grants from the National Natural Science Foundation of China (32271034,32070964,81971309,32170980,and 32300791)National Key Research and Development Program of China (2021ZD0201703)+4 种基金Chongqing Natural Science Fund for Distinguished Young Scholars (CSTB2023NSCQ-JQX0030)Guangdong Basic and Applied Basic Research Foundation (2022B1515020012,2021A1515110268,2023A1515010651)Shenzhen Medical Research Fund (A2303014)Shenzhen Fundamental Research Program (JCYJ20210324123212035,RCYX20200714114644167,ZDSYS20220606100801003,RCBS20210706092411028,and JCYJ20210324121214039)Shenzhen Key Laboratory of Chinese Medicine Active Substance Screening and Translational Research (ZDSYS20220606100801003).
文摘Oligodendrocyte precursor cells(OPCs)are a heterogeneous multipotent population in the central nervous system(CNS)that appear during embryogenesis and persist as resident cells in the adult brain parenchyma.OPCs could generate oligodendrocytes to participate in myelination.Recent advances have renewed our knowledge of OPC biology by discovering novel markers of oligodendroglial cells,the myelin-independent roles of OPCs,and the regulatory mechanism of OPC development.In this review,we will explore the updated knowledge on OPC identity,their multifaceted roles in the CNS in health and diseases,as well as the regulatory mechanisms that are involved in their developmental stages,which hopefully would contribute to a further understanding of OPCs and attract attention in the field of OPC biology.
