The persistent stability of ruthenium dioxide(RuO_(2))in acidic oxygen evolution reactions(OER)is compromised by the involvement of lattice oxygen(LO)and metal dissolution during the OER process.Heteroatom doping has ...The persistent stability of ruthenium dioxide(RuO_(2))in acidic oxygen evolution reactions(OER)is compromised by the involvement of lattice oxygen(LO)and metal dissolution during the OER process.Heteroatom doping has been recognized as a viable strategy to foster the stability of RuO_(2)for acidic OER applications.This study presented an ion that does not readily gain or lose electrons,Ba^(2+),into RuO_(2)(Ba-RuO_(2))nanosheet(NS)catalyst that increased the number of exposed active sites,achieving a current density of 10 mA/cm^(2)with an overpotential of only 229 mV and sustaining this output for over 250 h.According to density functional theory(DFT)and X-ray absorption spectroscopy,Ba doping resulted in a longer Ru-O bond length,which in turn diminished the covalency of the bond.This alteration curtailed the involvement of LO and the dissolution of ruthenium(Ru),thereby markedly improving the durability of the catalyst over extended periods.Additionally,attenuated total reflectance-surface enhanced infrared absorption spectroscopy analysis substantiated that the OER mechanism shifted from a LO-mediated pathway to an adsorbate evolution pathway due to Ba doping,thereby circumventing Ru over-oxidation and further enhancing the stability of RuO_(2).Furthermore,DFT findings uncovered that Ba doping optimizes the adsorption energy of intermediates,thus enhancing the OER activity in acidic environments.This study offers a potent strategy to guide future developments on Ru-based oxide catalysts'stability in an acidic environment.展开更多
Field tests have demonstrated that depressurization with controlled sand production is an effective technique for natural gas hydrate extraction.Variations in depositional environments and processes result in signific...Field tests have demonstrated that depressurization with controlled sand production is an effective technique for natural gas hydrate extraction.Variations in depositional environments and processes result in significant heterogeneity within subsea natural gas hydrate-bearing sediments.However,the influence of permeability heterogeneity on production performance during depressurization with controlled sand production remains inadequately understood.In this study,a multiphase,multi-component mathematical model is developed to simulate depressurization with controlled sand production in methane hydrate-bearing sediments,incorporating geological conditions representative of unconsolidated argillaceous siltstone hydrate deposits in the Shenhu area of the South China Sea.The effects of permeability heterogeneity-specifically,horizontal autocorrelation length and global permeability heterogeneity-on production performance during depressurization with sand production are investigated using geostatistical modeling combined with finite difference method based numerical simulations.Results show that as the horizontal autocorrelation length of permeability distribution increases,cumulative gas production first rises and then declines,reaching its peak at λ_(Dh)=0.1,whereas sand production steadily increases.In addition,higher formation permeability heterogeneity results in increased cumulative gas and sand production,suggesting that greater heterogeneity promotesmethane hydrate decomposition and gas recovery.These findings can offer valuable insights for optimizing future field development of hydrate-bearing sediments by depressurization with controlled sand production.展开更多
Nitrate synthesis is an important process for agriculture and industry,but suffers from energy-intensive steps including the synthesis and subsequent oxidation of ammonia.Herein,we present a selective N_(2)transformat...Nitrate synthesis is an important process for agriculture and industry,but suffers from energy-intensive steps including the synthesis and subsequent oxidation of ammonia.Herein,we present a selective N_(2)transformation to nitrate by guiding the charge neutralization of self-electrified water microdroplets in an artificial cloud generated with the portable ultrasonic atomizer.The electron and ion transfer in the charge neutralization of water microdroplets on metal micromesh enables an up to~40-fold increase in the reactivity of nitrate formation reaction driven by ultrasonic energy.A robust semi-continuous N_(2)oxidation by a Ni-mesh-screened cloud system was achieved,providing nitrate with~12 mM concentration every 20 h.These findings emphasize the potential of harnessing the microdroplet-mediated cloud electrochemistry of N_(2)in decentralizing the current mass production of fertilizer.展开更多
Ru-based nanomaterials have been demonstrated to be highly active electrocatalysts for hydrogen evo-lution reaction(HER),yet weak water adsorption and splitting ability in neutral media thus it is rather difficult for...Ru-based nanomaterials have been demonstrated to be highly active electrocatalysts for hydrogen evo-lution reaction(HER),yet weak water adsorption and splitting ability in neutral media thus it is rather difficult for the intermediates to adsorb on the active site.Herein,we introduce a concept of the prox-imity effect,com prising adjacent Ru and RuO_(2) nanoparticles coupled on TiO_(2)(Ru/RuO_(2)-TiO_(2)),for the synergic promotion of water molecule adsorption and splitting,significantly enhancing HER electrocatal-ysis performance.The in-situ spectroscopy experiments and density function theory(DFT)simulations demonstrated that the proximity effect between the adjacent Ru nanoparticles and RuO_(2) nanoparticles can accelerate water adsorption and splitting.As a result,the as-made Ru/RuO_(2)-TiO_(2) only need overpo-tentials of 52.7,16.0,and 16.4 mV to achieve the current density of 10 mA cm-2 in neutral,acid,and alkaline media,respectively.The mass activity of Ru/RuO_(2)-TiO_(2) in neutral media is 320 and 117 times higher than that of commercial Ru/C and Pt/C at the overpotential of 100 mV,respectively.This work emphasizes the proximity effect for activation of reactants which can be extended to other electrocat-alytic reactions.展开更多
With the spread and development of new epidemics,it is of great reference value to identify the changing trends of epidemics in public emotions.We designed and implemented the COVID-19 public opinion monitoring system...With the spread and development of new epidemics,it is of great reference value to identify the changing trends of epidemics in public emotions.We designed and implemented the COVID-19 public opinion monitoring system based on time series thermal new word mining.A new word structure discovery scheme based on the timing explosion of network topics and a Chinese sentiment analysis method for the COVID-19 public opinion environment are proposed.Establish a“Scrapy-Redis-Bloomfilter”distributed crawler framework to collect data.The system can judge the positive and negative emotions of the reviewer based on the comments,and can also reflect the depth of the seven emotions such as Hopeful,Happy,and Depressed.Finally,we improved the sentiment discriminant model of this system and compared the sentiment discriminant error of COVID-19 related comments with the Jiagu deep learning model.The results show that our model has better generalization ability and smaller discriminant error.We designed a large data visualization screen,which can clearly show the trend of public emotions,the proportion of various emotion categories,keywords,hot topics,etc.,and fully and intuitively reflect the development of public opinion.展开更多
Tetracycline is a typical antibiotic commonly used in various industries which is eco-toxic and quickly causes bacterial resistance.Therefo re,studying the efficient removal of tetracycline is necessary to protect the...Tetracycline is a typical antibiotic commonly used in various industries which is eco-toxic and quickly causes bacterial resistance.Therefo re,studying the efficient removal of tetracycline is necessary to protect the water environment.Herein,a novel Ce/Fe nanoparticle composite(1CCFO)was prepared by the sol-gel method and its removal effects of tetracycline under visible light were performed.The relationship between physicochemical properties of catalyst and photocatalytic degradation effects of tetracycline was analyzed based on a series of characterizations data such as X-ray diffraction(XRD),Raman spectro scopy,a vibrating sample magnetometer(VSM),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)method,X-ray photoelectron spectroscopy(XPS),and ultraviolet-visible(UV-Vis)spectroscopy.The results show that Ce/Fe photocatalyst possesses a large specific surface area,good visible light response,abundant oxygen vacancies and excellent redox performance,exhibiting good adsorption capacity,remarkable catalytic performance and stability.The optimal conditions for tetracycline removal were explored through orthogonal experiments.About 88%of tetracycline can be photodegraded in 1 h under optimal conditions.The possible decomposition pathways,main reactive oxygen species and suitable mechanism of the photocatalytic system were studied by liquid chromatography-mass spectro metry(LC-MS),an electron spin resonance(ESR)spectrometer and free radical quenching experiments.The results show that 1CCFO has an efficient degradation effect on tetracycline under visible light,which provides a feasible method to improve the performance of 1CCFO.展开更多
The lignification triggered by biotic or abiotic stresses hardens fruits and vegetables and eventually influences their consumer appeal.Extensive prior efforts have been made to unveil the underlying mechanism of fles...The lignification triggered by biotic or abiotic stresses hardens fruits and vegetables and eventually influences their consumer appeal.Extensive prior efforts have been made to unveil the underlying mechanism of flesh lignification,primarily focused on its physicochemical and molecular biological properties.Nevertheless,most of these studies used destroyed and homogenized bulk tissues as analytes;as a result,potentially valuable spatial information was lost.In this study,the deposition of lignin in loquat flesh during lignification was visualized from the tissue level to the singlecell level by combining the advantages of stimulated Raman scattering(SRS)and spontaneous Raman microscopy using label-free in situ molecular imaging.SRS has the advantages of being fast and providing large-area chemical imaging to reveal the spatial heterogeneity of lignin and cell wall polysaccharide distribution in loquat flesh.After 2 days of storage at 0℃,increased lignins were observed by large-area SRS imaging.In addition,microscopic SRS images of the flesh cells indicated that the increased lignins were trapped in the cell corner(CC)and middle lamella(ML).Furthermore,the compositional and structural features of lignified cells(LCs),CC and ML of loquat flesh were investigated by spontaneous Raman microscopy,and the results showed that the LCs were a combination of lignin,cellulose,and hemicellulose,whereas CC and ML showed only deposited lignin and pectin without cross-linked cellulose and hemicellulose.This result further suggests that the lignins in the CC and ML regions of loquats were later synthesized alone during postharvest storage.This innovative combination of SRS and spontaneous Raman microscopy allows the label-free macroscale and fine chemical imaging of plant cell walls and will enhance our fundamental understanding of the structures and functions of the plant cell wall.展开更多
Objective: To screen out a set of candidate genes which could help to determine whether patients with hypopharyngeal squamous cell carcinoma (HSCC) could benefit from docetaxel, cisplatin and 5-fluorouracil (TPF) indu...Objective: To screen out a set of candidate genes which could help to determine whether patients with hypopharyngeal squamous cell carcinoma (HSCC) could benefit from docetaxel, cisplatin and 5-fluorouracil (TPF) induction chemotherapy. Methods: Gene-expression profiles in 12 TPF-sensitive patients were compared to 9 resistant controls by microarray analysis. Subsequently, expression levels of potential biomarkers in chemosensitive cell line FaDu after TPF treatment were observed by quantitative real-time polymerase chain reaction (qRT-PCR). Results: Through microarray analysis, 1,579 differentially expressed genes were identified, of which 815 were up-regulated in TPF chemotherapy-responsive tissues whereas 764 were down-regulated. Gene ontology (GO) analysis suggested these genes participating in physiological processes including transcription and its regulation, cellular signal transduction and metabolic process. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that MAPK and Jat/STAT signaling pathways occupied important roles in TPF chemotherapeutic sensitivity. Moreover, in vitro cell culture experiments revealed the expression alternations of IL-6, MAPK14, JUN, CDK5 and CAMK2A exposed to TPF treatment by qRT-PCR, whilst providing an insight into the mechanism underlying TPF chemotherapeutic response in HSCC. Conclusions: These results provided a battery of genes related to TPF chemotherapeutic sensitivity and might act as molecular targets in HSCC treatment. Moreover, these candidate biomarkers could contribute to HSCC individualized treatment.展开更多
Rapid histology of brain tissues with sufficient diagnostic information has the great potential to aid neurosurgons during operations.Stimulated Raman Scattering(SRS)microscopy is an emerging label-free imaging techni...Rapid histology of brain tissues with sufficient diagnostic information has the great potential to aid neurosurgons during operations.Stimulated Raman Scattering(SRS)microscopy is an emerging label-free imaging technique,with the intrinsic chemical resolutions to delineate brain tumors from normal tissues without the nood of time-consuming tissue processing.Growing number of studies have shown SRS as a“virtual histology"tool for rapid diagnosis of various types of brain tumors.In this review,we focus on the basic principles and current developments of SRS microscopy,as well as its applications for brain tumor imaging.展开更多
Hard-magnetic soft materials have attracted broad interests because of their flexible programmability,non-contact activation and rapid response in various applications such as soft robotics,biomedical devices and flex...Hard-magnetic soft materials have attracted broad interests because of their flexible programmability,non-contact activation and rapid response in various applications such as soft robotics,biomedical devices and flexible electronics.Such multifunctional materials consist of a soft matrix embedded with hard-magnetic particles,and can exhibit large deformations under external magnetic stimuli.Here,we develop a three-dimensional(3D)rod model to predict spatial deformations(extension,bending and twist)of slender hard-magnetic elastica.The model follows Kirchhoff hypothesis and thus reduces the 3D magneto-elastic energy function to a one-dimensional(1D)form.Besides,the co-rotational formulation is applied to describe rigid body motion,and explicit time integration is adopted for the nonlinear resolution.Moreover,we explore finite bending,post-buckling and twisting of hard-magnetic elastica under external magnetic fields with different directions and amplitudes.Representative examples with various configurations show superior efficiency and accuracy of the model(the difference less than 1%with only a small number of elements)compared to conventional solid element.Our model could be used to guide rational designs on programmable shape morphing of ferromagnetic slender structures.展开更多
Purpose： This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance （HOMA-IR） are maintained after discontinuation of intervention in the overweight/obese （OWOB） women...Purpose： This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance （HOMA-IR） are maintained after discontinuation of intervention in the overweight/obese （OWOB） women. Methods： The study subjects were from 2 independent studies with similar aerobic exercise （AE） intervention programs. In study I, I50WOB postmenopausal women with pre-diabetes （body mass index, BMI = 24-33 kg/m2, aged 52-65 years） completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study lI, 12 OWOB （BM1 = 25-35 kg/m2, aged 30-50 years） premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60%-75% of initial fitness level, 30-60 min/time and 3-5 times/week. Fat mass （FM） was assessed by Dual Energy X-ray Absorptiometry （DXA Prodigy; study I） or bioelectrical impedance device （Inbody 720; study II）. Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated. Results： Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR （-18.9%, p = 0.012 and -26.7%, p = 0.046, respectively）, and 8-month AE reduced FM at upper abdominal region （-6.2%, p = 0.021）. However, these improvements were not maintained in either study at the follow-up. Conclusion： The AE program used in these studies was effective to reduce insulin resistance and/or FM in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.展开更多
The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medi...The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medicine and safety inspections,has increased the exposure risk of irradiation safety workers.Traditional irradiation detectors are stiff and incompatible with the skin,and lack human health monitoring function,thus it’s vital to apply these flexible sensors for irradiation warning.Here,we report a novel composite gel device synthesized through solution processes by combining the Cs_(3)Cu_(2)I_(5):Zn nanoscintillator with the pre-patterned biocompatible gel,exhibiting a bi-functional response to motion/vibration sensing and sensitive irradiation warning.These wearable devices achieve a pressure sensitivity of up to 34 kPa^(-1)in a low-pressure range (0–3 kPa),a low limit of detection (LoD) down to 1.4 Pa,enabling health monitoring functions of pulse monitoring,finger bending,and elbow bending.Simultaneously,the device scintillates under X-ray irradiation among a wide dose rate range of 54–1167μGy_(air)s^(-1).The robust device shows no obvious signal loss after 4000 compression cycles and also excellent irradiation resistance over 50 days,broadening the path for designing and realizing new functional wearable devices.展开更多
Due to the enigmatical electrostatic potential difference between the inside and outside layers,the relationship between the diameter and the photocatalytic property of the Janus transition metal dichalcogenides nanot...Due to the enigmatical electrostatic potential difference between the inside and outside layers,the relationship between the diameter and the photocatalytic property of the Janus transition metal dichalcogenides nanotube is still unclear.In this job,for the first time we calculate the electrostatic potential difference of the Janus WSSe armchair nanotubes with corresponding building block models through the first principles calculations.The electrostatic potential difference increases as the diameter increases.Then,it is observed that the WSSe armchair nanotubes with smaller diameter have stronger oxidation capacity,weaker reduction capacity,and higher solar-to-hydrogen conversion efficiency.Furthermore,the diminution of diameter could make the band gap drop,and even cause a direct-indirect transformation of band structure.The adjustment of diameter could also regulate the ability of adsorbing water molecules at the insider and outside layers.Moreover,the suitable band edge positions,wide optical absorbance region(to the near-infrared),outstanding solar-to-hydrogen efficiency(up to 28.99%),high carrier separation,adequate photoexcited carrier driving forces,as well as the energetic and thermal stability,render these nanotubes befitting the photocata lytic water-splitting application.Our study not only predicts a kind of ideal water-splitting photocatalyst,but also shows an effective way to improve their photocatalytic performances.展开更多
The global Internet is a complex network of interconnected autonomous systems(ASes).Understanding Internet inter-domain path information is crucial for understanding,managing,and improving the Internet.The path inform...The global Internet is a complex network of interconnected autonomous systems(ASes).Understanding Internet inter-domain path information is crucial for understanding,managing,and improving the Internet.The path information can also help protect user privacy and security.However,due to the complicated and heterogeneous structure of the Internet,path information is not publicly available.Obtaining path information is challenging due to the limited measurement probes and collectors.Therefore,inferring Internet inter-domain paths from the limited data is a supplementary approach to measure Internet inter-domain paths.The purpose of this survey is to provide an overview of techniques that have been conducted to infer Internet inter-domain paths from 2005 to 2023 and present the main lessons from these studies.To this end,we summarize the inter-domain path inference techniques based on the granularity of the paths,for each method,we describe the data sources,the key ideas,the advantages,and the limitations.To help readers understand the path inference techniques,we also summarize the background techniques for path inference,such as techniques to measure the Internet,infer AS relationships,resolve aliases,and map IP addresses to ASes.A case study of the existing techniques is also presented to show the real-world applications of inter-domain path inference.Additionally,we discuss the challenges and opportunities in inferring Internet inter-domain paths,the drawbacks of the state-of-the-art techniques,and the future directions.展开更多
Introduction Strengthening intellectual property protection has become a main theme in China today.With the increasing frequency of infringements on intellectual property rights,how to protect intellectual property ri...Introduction Strengthening intellectual property protection has become a main theme in China today.With the increasing frequency of infringements on intellectual property rights,how to protect intellectual property rights has become a problem that many rights holders are currently considering.While it was previously a common practice that countries provide both judicial and administrative means for protecting IP,practice has shown that administrative IP protection has been particularly useful and effective in China because of China’s national conditions,i.e.the tradition of having an effective and all-encompassing government that dates back thousands of years and continues until today.展开更多
This work presents an electrochemical study of enhanced electronic communication based on intermolecular hydrogen-bonding in ferrocenemethanol （described as FcCH2OH） molecular clusters. The enhanced electronic commu...This work presents an electrochemical study of enhanced electronic communication based on intermolecular hydrogen-bonding in ferrocenemethanol （described as FcCH2OH） molecular clusters. The enhanced electronic communication in FcCH2OH clusters is confirmed and further investigated by differential-pulse voltammetry and cyclic voltammetry. A key finding is that this enhanced electronic communication increases the standard rate constant of the electron transfer process. These results will provide us with a further understanding of the electronic communication within the ferrocenyl derivariv~ which it ha^pd nn rhp inr^rmnlpcldar hvdrn^en-hnndinct展开更多
Given the importance of web search volume for reflecting tourists'preferences for certain tourism services and destinations,incorporating these data into forecasting models can significantly improve forecasting pe...Given the importance of web search volume for reflecting tourists'preferences for certain tourism services and destinations,incorporating these data into forecasting models can significantly improve forecasting performance.This study enriches the literature on tourism demand forecasting and tourists'search behavior through segmented Baidu search volume data.First,this study divides Baidu search volume data based on volume sources and periods.Then,by analyzing the most relevant keywords in tourism demand in different segments,this study captures the dynamic characteristics of tourist search behavior.Finally,this study adopts a series of econometric and machine learning models to further improve the performance of tourism demand and forecasting.The findings indicate that tourists’search behavior has changed significantly with the prevalence and popularization of 4G technology and suggest that search volume improves forecasting performance,especially search volume on mobile terminals,from 2014M1–2019M12.展开更多
Young moso bamboo shoots are a popular seasonal food and an important source of income for farmers,with value for cultivation estimated at$30,000 per hectare.Bamboo also has great environmental importance and its uniq...Young moso bamboo shoots are a popular seasonal food and an important source of income for farmers,with value for cultivation estimated at$30,000 per hectare.Bamboo also has great environmental importance and its unique physiology is of scientific interest.A rare and valuable phenomenon has recently appeared where a large number of adjacent buds within a single moso bamboo rhizome have grown into shoots.Although of practical importance for the production of edible shoots,such occurrences have not been scientifically studied,due to their rarity.Analysis of collected reports from enhanced shoot production events in China showed no evidence that enhanced shoot development was heritable.We report the analysis of the rhizosphere microbiome from a rhizome with 18 shoots,compared to rhizomes having one or no shoots as controls.The community of prokaryotes,but not fungi,correlated with the shoot number.Burkholderia was the most abundant genus,which was negatively correlated with rhizome shoot number,while Clostridia and Ktedonobacteria were positively correlated.Two Burkholderia strains were isolated and their plant-growth promoting activity was tested.The isolated Burkholderia strains attenuated the growth of bamboo seedlings.These data provide the first study on excessive shoot development in bamboo,which will facilitate hypothesis building for future studies.展开更多
The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bid...The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bidirectional consistency verification of function and fault paths.This paper proposes an innovative GO-FTA-GERTS dual model that integrates goal-oriented(GO)methods,fault tree analysis(FTA),and graphical evaluation and review technique(GERT)networks.The core innovation lies in constructing a bidirectional logical interlocking mechanism between the GO success tree and the FTA failure tree,leveraging the dynamic state transfer characteristics of GERT to achieve mathematical equivalence verification of function paths and fault paths.Using a specific aircraft ejection subsystem as an example,the model demonstrates excellent accuracy in ultra-low failure probability calculations:the mean system failure probability calculated by the FTA-GERT network is approximately 5.26×10^(−10) per flight hour,meeting airworthiness standards.At the same time,Monte Carlo simulation and Welch’s t-test are also used to verify that the success probability of GO-GERT model is strictly complementary to the system failure probability calculated by FTA-GERT network.This novel model effectively addresses the limitations of static analysis,dynamic path quantification,and rare event evaluation,providing a new method for reliability analysis of critical aviation safety systems.展开更多
基金supported by Young Project of Education Department in Guizhou Province(No.2022099)the Natural Science Special of Guizhou University(No.X202220 Special Post A)the National Natural Science Foundation of China(Grant No.22208071)。
文摘The persistent stability of ruthenium dioxide(RuO_(2))in acidic oxygen evolution reactions(OER)is compromised by the involvement of lattice oxygen(LO)and metal dissolution during the OER process.Heteroatom doping has been recognized as a viable strategy to foster the stability of RuO_(2)for acidic OER applications.This study presented an ion that does not readily gain or lose electrons,Ba^(2+),into RuO_(2)(Ba-RuO_(2))nanosheet(NS)catalyst that increased the number of exposed active sites,achieving a current density of 10 mA/cm^(2)with an overpotential of only 229 mV and sustaining this output for over 250 h.According to density functional theory(DFT)and X-ray absorption spectroscopy,Ba doping resulted in a longer Ru-O bond length,which in turn diminished the covalency of the bond.This alteration curtailed the involvement of LO and the dissolution of ruthenium(Ru),thereby markedly improving the durability of the catalyst over extended periods.Additionally,attenuated total reflectance-surface enhanced infrared absorption spectroscopy analysis substantiated that the OER mechanism shifted from a LO-mediated pathway to an adsorbate evolution pathway due to Ba doping,thereby circumventing Ru over-oxidation and further enhancing the stability of RuO_(2).Furthermore,DFT findings uncovered that Ba doping optimizes the adsorption energy of intermediates,thus enhancing the OER activity in acidic environments.This study offers a potent strategy to guide future developments on Ru-based oxide catalysts'stability in an acidic environment.
基金funded by the National Key Research and Development Program of China(grant number 2023YFC3009204)the National Natural Science Foundation of China(grant number 52174015).
文摘Field tests have demonstrated that depressurization with controlled sand production is an effective technique for natural gas hydrate extraction.Variations in depositional environments and processes result in significant heterogeneity within subsea natural gas hydrate-bearing sediments.However,the influence of permeability heterogeneity on production performance during depressurization with controlled sand production remains inadequately understood.In this study,a multiphase,multi-component mathematical model is developed to simulate depressurization with controlled sand production in methane hydrate-bearing sediments,incorporating geological conditions representative of unconsolidated argillaceous siltstone hydrate deposits in the Shenhu area of the South China Sea.The effects of permeability heterogeneity-specifically,horizontal autocorrelation length and global permeability heterogeneity-on production performance during depressurization with sand production are investigated using geostatistical modeling combined with finite difference method based numerical simulations.Results show that as the horizontal autocorrelation length of permeability distribution increases,cumulative gas production first rises and then declines,reaching its peak at λ_(Dh)=0.1,whereas sand production steadily increases.In addition,higher formation permeability heterogeneity results in increased cumulative gas and sand production,suggesting that greater heterogeneity promotesmethane hydrate decomposition and gas recovery.These findings can offer valuable insights for optimizing future field development of hydrate-bearing sediments by depressurization with controlled sand production.
基金supported by the National Key R&D Program of China(2022YFA1504603)the National Natural Science Foundation of China(22025206,22172163)+1 种基金the Dalian Innovation Support Plan for High Level Talents(2022RG13)the Fundamental Research Funds for the Central Universities(20720220008)。
文摘Nitrate synthesis is an important process for agriculture and industry,but suffers from energy-intensive steps including the synthesis and subsequent oxidation of ammonia.Herein,we present a selective N_(2)transformation to nitrate by guiding the charge neutralization of self-electrified water microdroplets in an artificial cloud generated with the portable ultrasonic atomizer.The electron and ion transfer in the charge neutralization of water microdroplets on metal micromesh enables an up to~40-fold increase in the reactivity of nitrate formation reaction driven by ultrasonic energy.A robust semi-continuous N_(2)oxidation by a Ni-mesh-screened cloud system was achieved,providing nitrate with~12 mM concentration every 20 h.These findings emphasize the potential of harnessing the microdroplet-mediated cloud electrochemistry of N_(2)in decentralizing the current mass production of fertilizer.
基金supported by the Young Project of the Education Department in Guizhou Province(No.2022099)the Natural Science Special of Guizhou University(No.X202220 Special Post A).
文摘Ru-based nanomaterials have been demonstrated to be highly active electrocatalysts for hydrogen evo-lution reaction(HER),yet weak water adsorption and splitting ability in neutral media thus it is rather difficult for the intermediates to adsorb on the active site.Herein,we introduce a concept of the prox-imity effect,com prising adjacent Ru and RuO_(2) nanoparticles coupled on TiO_(2)(Ru/RuO_(2)-TiO_(2)),for the synergic promotion of water molecule adsorption and splitting,significantly enhancing HER electrocatal-ysis performance.The in-situ spectroscopy experiments and density function theory(DFT)simulations demonstrated that the proximity effect between the adjacent Ru nanoparticles and RuO_(2) nanoparticles can accelerate water adsorption and splitting.As a result,the as-made Ru/RuO_(2)-TiO_(2) only need overpo-tentials of 52.7,16.0,and 16.4 mV to achieve the current density of 10 mA cm-2 in neutral,acid,and alkaline media,respectively.The mass activity of Ru/RuO_(2)-TiO_(2) in neutral media is 320 and 117 times higher than that of commercial Ru/C and Pt/C at the overpotential of 100 mV,respectively.This work emphasizes the proximity effect for activation of reactants which can be extended to other electrocat-alytic reactions.
基金This work was supported by the Hainan Provincial Natural Science Foundation of China[2019RC041,2019RC098]National Natural Science Foundation of China[61762033]+3 种基金Hainan University Doctor Start Fund Project[kyqd1328]Hainan University Youth Fund Project[qnjj1444]Ministry of education humanities and social sciences research program fund project(19YJA710010)The Opening Project of Shanghai Trusted Industrial Control Platform(Grant No.TICPSH202003005-ZC).
文摘With the spread and development of new epidemics,it is of great reference value to identify the changing trends of epidemics in public emotions.We designed and implemented the COVID-19 public opinion monitoring system based on time series thermal new word mining.A new word structure discovery scheme based on the timing explosion of network topics and a Chinese sentiment analysis method for the COVID-19 public opinion environment are proposed.Establish a“Scrapy-Redis-Bloomfilter”distributed crawler framework to collect data.The system can judge the positive and negative emotions of the reviewer based on the comments,and can also reflect the depth of the seven emotions such as Hopeful,Happy,and Depressed.Finally,we improved the sentiment discriminant model of this system and compared the sentiment discriminant error of COVID-19 related comments with the Jiagu deep learning model.The results show that our model has better generalization ability and smaller discriminant error.We designed a large data visualization screen,which can clearly show the trend of public emotions,the proportion of various emotion categories,keywords,hot topics,etc.,and fully and intuitively reflect the development of public opinion.
基金the National Natural Science Foundation of China(21978061)Zhejiang Provincial Natural Science Foundation of China(LY19B060007)Zhejiang Key Laboratory of Green Pesticides and Cleaner Production Technology。
文摘Tetracycline is a typical antibiotic commonly used in various industries which is eco-toxic and quickly causes bacterial resistance.Therefo re,studying the efficient removal of tetracycline is necessary to protect the water environment.Herein,a novel Ce/Fe nanoparticle composite(1CCFO)was prepared by the sol-gel method and its removal effects of tetracycline under visible light were performed.The relationship between physicochemical properties of catalyst and photocatalytic degradation effects of tetracycline was analyzed based on a series of characterizations data such as X-ray diffraction(XRD),Raman spectro scopy,a vibrating sample magnetometer(VSM),scanning electron microscopy(SEM),Brunauer-Emmett-Teller(BET)method,X-ray photoelectron spectroscopy(XPS),and ultraviolet-visible(UV-Vis)spectroscopy.The results show that Ce/Fe photocatalyst possesses a large specific surface area,good visible light response,abundant oxygen vacancies and excellent redox performance,exhibiting good adsorption capacity,remarkable catalytic performance and stability.The optimal conditions for tetracycline removal were explored through orthogonal experiments.About 88%of tetracycline can be photodegraded in 1 h under optimal conditions.The possible decomposition pathways,main reactive oxygen species and suitable mechanism of the photocatalytic system were studied by liquid chromatography-mass spectro metry(LC-MS),an electron spin resonance(ESR)spectrometer and free radical quenching experiments.The results show that 1CCFO has an efficient degradation effect on tetracycline under visible light,which provides a feasible method to improve the performance of 1CCFO.
基金supported by the National Key R&D Program of China(2016YFD0400106)National Natural Science Foundation of China(31630067,31671902,31401541,81671725)+1 种基金Talent Project of Zhejiang Association for Science and Technology(2018YCGC006)the 111 Project(B17039).
文摘The lignification triggered by biotic or abiotic stresses hardens fruits and vegetables and eventually influences their consumer appeal.Extensive prior efforts have been made to unveil the underlying mechanism of flesh lignification,primarily focused on its physicochemical and molecular biological properties.Nevertheless,most of these studies used destroyed and homogenized bulk tissues as analytes;as a result,potentially valuable spatial information was lost.In this study,the deposition of lignin in loquat flesh during lignification was visualized from the tissue level to the singlecell level by combining the advantages of stimulated Raman scattering(SRS)and spontaneous Raman microscopy using label-free in situ molecular imaging.SRS has the advantages of being fast and providing large-area chemical imaging to reveal the spatial heterogeneity of lignin and cell wall polysaccharide distribution in loquat flesh.After 2 days of storage at 0℃,increased lignins were observed by large-area SRS imaging.In addition,microscopic SRS images of the flesh cells indicated that the increased lignins were trapped in the cell corner(CC)and middle lamella(ML).Furthermore,the compositional and structural features of lignified cells(LCs),CC and ML of loquat flesh were investigated by spontaneous Raman microscopy,and the results showed that the LCs were a combination of lignin,cellulose,and hemicellulose,whereas CC and ML showed only deposited lignin and pectin without cross-linked cellulose and hemicellulose.This result further suggests that the lignins in the CC and ML regions of loquats were later synthesized alone during postharvest storage.This innovative combination of SRS and spontaneous Raman microscopy allows the label-free macroscale and fine chemical imaging of plant cell walls and will enhance our fundamental understanding of the structures and functions of the plant cell wall.
基金supported by grants of the Beijing Municipal Science&Technology Commission(No.Z141107002514003)Beijing Municipal Administration of Hospital Clinical Medicine Development of Special Funding Support(Code.XMLX201311)the Priming Scientific Research Foundation for the Junior Researcher in Beijing Tongren Hospital,Capital Medical University(2015-YJJ-ZZL-001)
文摘Objective: To screen out a set of candidate genes which could help to determine whether patients with hypopharyngeal squamous cell carcinoma (HSCC) could benefit from docetaxel, cisplatin and 5-fluorouracil (TPF) induction chemotherapy. Methods: Gene-expression profiles in 12 TPF-sensitive patients were compared to 9 resistant controls by microarray analysis. Subsequently, expression levels of potential biomarkers in chemosensitive cell line FaDu after TPF treatment were observed by quantitative real-time polymerase chain reaction (qRT-PCR). Results: Through microarray analysis, 1,579 differentially expressed genes were identified, of which 815 were up-regulated in TPF chemotherapy-responsive tissues whereas 764 were down-regulated. Gene ontology (GO) analysis suggested these genes participating in physiological processes including transcription and its regulation, cellular signal transduction and metabolic process. Additionally, Kyoto Encyclopedia of Genes and Genomes (KEGG) database revealed that MAPK and Jat/STAT signaling pathways occupied important roles in TPF chemotherapeutic sensitivity. Moreover, in vitro cell culture experiments revealed the expression alternations of IL-6, MAPK14, JUN, CDK5 and CAMK2A exposed to TPF treatment by qRT-PCR, whilst providing an insight into the mechanism underlying TPF chemotherapeutic response in HSCC. Conclusions: These results provided a battery of genes related to TPF chemotherapeutic sensitivity and might act as molecular targets in HSCC treatment. Moreover, these candidate biomarkers could contribute to HSCC individualized treatment.
基金supports from the National Key Research and Development Program of China (2016YFC0102100,2016YFA0301000,2016YFA0203900)National Natural Science Foundation of China (81671725)+1 种基金Shanghai Rising Star Program (15QA1400500)Shanghai Action Plan for Scientific and Technological Innovation Program (16441909200).
文摘Rapid histology of brain tissues with sufficient diagnostic information has the great potential to aid neurosurgons during operations.Stimulated Raman Scattering(SRS)microscopy is an emerging label-free imaging technique,with the intrinsic chemical resolutions to delineate brain tumors from normal tissues without the nood of time-consuming tissue processing.Growing number of studies have shown SRS as a“virtual histology"tool for rapid diagnosis of various types of brain tumors.In this review,we focus on the basic principles and current developments of SRS microscopy,as well as its applications for brain tumor imaging.
基金This work was supported by the National Natural Science Foundation of China(Grants Nos.12122204,11872150,and 11890673)Shanghai Pilot Program for Basic Research-Fudan University(Grant No.21TQ1400100-21TQ010)+2 种基金Shanghai Shuguang Program(Grant No.21SG05)Shanghai Rising-Star Program(Grant No.19QA1400500)Young Scientist Project of Ministry of Education Innovation Platform.
文摘Hard-magnetic soft materials have attracted broad interests because of their flexible programmability,non-contact activation and rapid response in various applications such as soft robotics,biomedical devices and flexible electronics.Such multifunctional materials consist of a soft matrix embedded with hard-magnetic particles,and can exhibit large deformations under external magnetic stimuli.Here,we develop a three-dimensional(3D)rod model to predict spatial deformations(extension,bending and twist)of slender hard-magnetic elastica.The model follows Kirchhoff hypothesis and thus reduces the 3D magneto-elastic energy function to a one-dimensional(1D)form.Besides,the co-rotational formulation is applied to describe rigid body motion,and explicit time integration is adopted for the nonlinear resolution.Moreover,we explore finite bending,post-buckling and twisting of hard-magnetic elastica under external magnetic fields with different directions and amplitudes.Representative examples with various configurations show superior efficiency and accuracy of the model(the difference less than 1%with only a small number of elements)compared to conventional solid element.Our model could be used to guide rational designs on programmable shape morphing of ferromagnetic slender structures.
基金financially supported by the China State Sport General Administration(No.2013B040,2015B039)the University of J yvaskyla Wellness program and the Shanghai Jiao Tong University Zhiyuan Foundation(No.CP2014013)
文摘Purpose： This study aimed to assess whether the benefits of exercise on central adiposity and insulin resistance （HOMA-IR） are maintained after discontinuation of intervention in the overweight/obese （OWOB） women. Methods： The study subjects were from 2 independent studies with similar aerobic exercise （AE） intervention programs. In study I, I50WOB postmenopausal women with pre-diabetes （body mass index, BMI = 24-33 kg/m2, aged 52-65 years） completed an 8-month exercise intervention and were followed for 2 years after the intervention. In study lI, 12 OWOB （BM1 = 25-35 kg/m2, aged 30-50 years） premenopausal women participated in a 6-week AE and were followed for 4 years after the intervention. The exercise program consisted of progressive AE with intensity of 60%-75% of initial fitness level, 30-60 min/time and 3-5 times/week. Fat mass （FM） was assessed by Dual Energy X-ray Absorptiometry （DXA Prodigy; study I） or bioelectrical impedance device （Inbody 720; study II）. Plasma glucose and insulin were assessed by chemiluminescent immunoassay and HOMA-IR was calculated. Results： Both 8-month and 6-week moderate AE were effective in reducing HOMA-IR （-18.9%, p = 0.012 and -26.7%, p = 0.046, respectively）, and 8-month AE reduced FM at upper abdominal region （-6.2%, p = 0.021）. However, these improvements were not maintained in either study at the follow-up. Conclusion： The AE program used in these studies was effective to reduce insulin resistance and/or FM in central body region among overweight and obese women. However, when exercise intervention was discontinued, the beneficial effects following both short- and long-term intervention disappeared. Thus maintaining exercise seems to be required if one wants to reap the benefits of exercise in the long-term.
基金financially supported by the National Natural Science Foundation of China (No. 52173166 and 22105083)the Project of Science and Technology Development Plan of Jilin Province (No. 20230101025JC)+1 种基金Xiaomi Young Scholar Projectthe Fundamental Research Funds for the Central Universities, JLU, and JLUSTIRT (2017TD-06)。
文摘The well-developed multifunctional wearable electronic device has fed the demand for human medicine and health monitoring in complex situations.However,the advancement of nuclear technology,especially irradiation medicine and safety inspections,has increased the exposure risk of irradiation safety workers.Traditional irradiation detectors are stiff and incompatible with the skin,and lack human health monitoring function,thus it’s vital to apply these flexible sensors for irradiation warning.Here,we report a novel composite gel device synthesized through solution processes by combining the Cs_(3)Cu_(2)I_(5):Zn nanoscintillator with the pre-patterned biocompatible gel,exhibiting a bi-functional response to motion/vibration sensing and sensitive irradiation warning.These wearable devices achieve a pressure sensitivity of up to 34 kPa^(-1)in a low-pressure range (0–3 kPa),a low limit of detection (LoD) down to 1.4 Pa,enabling health monitoring functions of pulse monitoring,finger bending,and elbow bending.Simultaneously,the device scintillates under X-ray irradiation among a wide dose rate range of 54–1167μGy_(air)s^(-1).The robust device shows no obvious signal loss after 4000 compression cycles and also excellent irradiation resistance over 50 days,broadening the path for designing and realizing new functional wearable devices.
基金supported by the National Natural Science foundation of China(Nos.11804006 and U20041103)the Henan Key Program of Technology Research and Development(No.182102310907)+1 种基金the Henan College Key Research Project(No.19A430006)the China Scholarship Council(No.201908410036)。
文摘Due to the enigmatical electrostatic potential difference between the inside and outside layers,the relationship between the diameter and the photocatalytic property of the Janus transition metal dichalcogenides nanotube is still unclear.In this job,for the first time we calculate the electrostatic potential difference of the Janus WSSe armchair nanotubes with corresponding building block models through the first principles calculations.The electrostatic potential difference increases as the diameter increases.Then,it is observed that the WSSe armchair nanotubes with smaller diameter have stronger oxidation capacity,weaker reduction capacity,and higher solar-to-hydrogen conversion efficiency.Furthermore,the diminution of diameter could make the band gap drop,and even cause a direct-indirect transformation of band structure.The adjustment of diameter could also regulate the ability of adsorbing water molecules at the insider and outside layers.Moreover,the suitable band edge positions,wide optical absorbance region(to the near-infrared),outstanding solar-to-hydrogen efficiency(up to 28.99%),high carrier separation,adequate photoexcited carrier driving forces,as well as the energetic and thermal stability,render these nanotubes befitting the photocata lytic water-splitting application.Our study not only predicts a kind of ideal water-splitting photocatalyst,but also shows an effective way to improve their photocatalytic performances.
基金the China Postdoctoral Science Foundation(2023TQ0089)the National Natural Science Foundation of China(Nos.62072465,62172155)the Science and Technology Innovation Program of Hunan Province(Nos.2022RC3061,2023RC3027).
文摘The global Internet is a complex network of interconnected autonomous systems(ASes).Understanding Internet inter-domain path information is crucial for understanding,managing,and improving the Internet.The path information can also help protect user privacy and security.However,due to the complicated and heterogeneous structure of the Internet,path information is not publicly available.Obtaining path information is challenging due to the limited measurement probes and collectors.Therefore,inferring Internet inter-domain paths from the limited data is a supplementary approach to measure Internet inter-domain paths.The purpose of this survey is to provide an overview of techniques that have been conducted to infer Internet inter-domain paths from 2005 to 2023 and present the main lessons from these studies.To this end,we summarize the inter-domain path inference techniques based on the granularity of the paths,for each method,we describe the data sources,the key ideas,the advantages,and the limitations.To help readers understand the path inference techniques,we also summarize the background techniques for path inference,such as techniques to measure the Internet,infer AS relationships,resolve aliases,and map IP addresses to ASes.A case study of the existing techniques is also presented to show the real-world applications of inter-domain path inference.Additionally,we discuss the challenges and opportunities in inferring Internet inter-domain paths,the drawbacks of the state-of-the-art techniques,and the future directions.
文摘Introduction Strengthening intellectual property protection has become a main theme in China today.With the increasing frequency of infringements on intellectual property rights,how to protect intellectual property rights has become a problem that many rights holders are currently considering.While it was previously a common practice that countries provide both judicial and administrative means for protecting IP,practice has shown that administrative IP protection has been particularly useful and effective in China because of China’s national conditions,i.e.the tradition of having an effective and all-encompassing government that dates back thousands of years and continues until today.
基金the financial support from the National Natural Science Foundation of China(No. 21173023)National 111 Project of China(No. B07012)
文摘This work presents an electrochemical study of enhanced electronic communication based on intermolecular hydrogen-bonding in ferrocenemethanol （described as FcCH2OH） molecular clusters. The enhanced electronic communication in FcCH2OH clusters is confirmed and further investigated by differential-pulse voltammetry and cyclic voltammetry. A key finding is that this enhanced electronic communication increases the standard rate constant of the electron transfer process. These results will provide us with a further understanding of the electronic communication within the ferrocenyl derivariv~ which it ha^pd nn rhp inr^rmnlpcldar hvdrn^en-hnndinct
基金partly supported by the National Natural Science Foundation of China under Grant No.72101197by the Fundamental Research Funds for the Central Universities under Grant No.SK2021007.
文摘Given the importance of web search volume for reflecting tourists'preferences for certain tourism services and destinations,incorporating these data into forecasting models can significantly improve forecasting performance.This study enriches the literature on tourism demand forecasting and tourists'search behavior through segmented Baidu search volume data.First,this study divides Baidu search volume data based on volume sources and periods.Then,by analyzing the most relevant keywords in tourism demand in different segments,this study captures the dynamic characteristics of tourist search behavior.Finally,this study adopts a series of econometric and machine learning models to further improve the performance of tourism demand and forecasting.The findings indicate that tourists’search behavior has changed significantly with the prevalence and popularization of 4G technology and suggest that search volume improves forecasting performance,especially search volume on mobile terminals,from 2014M1–2019M12.
基金supported by the Qianjiang Talent D program to FCthe National Natural Science Foundation of China(grant no.31700224+4 种基金3187123331770543)the Zhejiang Science and Technology Major Program on Agricultural New Variety Breeding(grant no.2016C02056-1)the Program for Changjiang Scholars and Innovative Research Team in University(grant no.IRT_17R99 to SL)funded by the Academy of Finland Center of Excellence in Primary Producers 2014-2019(decisions#271832 and 307335).
文摘Young moso bamboo shoots are a popular seasonal food and an important source of income for farmers,with value for cultivation estimated at$30,000 per hectare.Bamboo also has great environmental importance and its unique physiology is of scientific interest.A rare and valuable phenomenon has recently appeared where a large number of adjacent buds within a single moso bamboo rhizome have grown into shoots.Although of practical importance for the production of edible shoots,such occurrences have not been scientifically studied,due to their rarity.Analysis of collected reports from enhanced shoot production events in China showed no evidence that enhanced shoot development was heritable.We report the analysis of the rhizosphere microbiome from a rhizome with 18 shoots,compared to rhizomes having one or no shoots as controls.The community of prokaryotes,but not fungi,correlated with the shoot number.Burkholderia was the most abundant genus,which was negatively correlated with rhizome shoot number,while Clostridia and Ktedonobacteria were positively correlated.Two Burkholderia strains were isolated and their plant-growth promoting activity was tested.The isolated Burkholderia strains attenuated the growth of bamboo seedlings.These data provide the first study on excessive shoot development in bamboo,which will facilitate hypothesis building for future studies.
基金supported by Shanghai Central Guidance Science and Technology Development Fund(NO:YDZX20233100004008)National Natural Science Foundation of China(NO:T2441003).
文摘The reliability assessment of aircraft ejection separation systems is crucial for aviation safety,but traditional methods exhibit significant shortcomings in dynamic behavior modeling,rare event quantification,and bidirectional consistency verification of function and fault paths.This paper proposes an innovative GO-FTA-GERTS dual model that integrates goal-oriented(GO)methods,fault tree analysis(FTA),and graphical evaluation and review technique(GERT)networks.The core innovation lies in constructing a bidirectional logical interlocking mechanism between the GO success tree and the FTA failure tree,leveraging the dynamic state transfer characteristics of GERT to achieve mathematical equivalence verification of function paths and fault paths.Using a specific aircraft ejection subsystem as an example,the model demonstrates excellent accuracy in ultra-low failure probability calculations:the mean system failure probability calculated by the FTA-GERT network is approximately 5.26×10^(−10) per flight hour,meeting airworthiness standards.At the same time,Monte Carlo simulation and Welch’s t-test are also used to verify that the success probability of GO-GERT model is strictly complementary to the system failure probability calculated by FTA-GERT network.This novel model effectively addresses the limitations of static analysis,dynamic path quantification,and rare event evaluation,providing a new method for reliability analysis of critical aviation safety systems.
