Reproductive hormones associated with the hypothalamic-pituitary-gonadal(HPG)axis are closely linked to bone homeostasis.In this study,we demonstrate that Gonadotropin inhibitory hormone(GnIH,one of the key reproducti...Reproductive hormones associated with the hypothalamic-pituitary-gonadal(HPG)axis are closely linked to bone homeostasis.In this study,we demonstrate that Gonadotropin inhibitory hormone(GnIH,one of the key reproductive hormones upstream of the HPG axis)plays an indispensable role in regulating bone homeostasis and maintaining bone mass.We find that deficiency of GnIH or its receptor Gpr147 leads to a significant reduction in bone mineral density(BMD)in mice primarily by enhancement of osteoclast activation in vivo and in vitro.Mechanistically,GnIH/Gpr147 inhibits osteoclastogenesis by the PI3K/AKT,MAPK,NF-κB and Nfatc1 signaling pathways.Furthermore,GnIH treatment was able to alleviate bone loss in aging,ovariectomy(OVX)or LPS-induced mice.Moreover,the therapy using green light promotes the release of GnIH and rescues OVX-induced bone loss.In humans,serum GnIH increases and bone resorption markers decrease after green light exposure.Therefore,our study elucidates that GnIH plays an important role in maintaining bone homeostasis via modulating osteoclast differentiation and demonstrates the potential of GnIH therapy or green light therapy in preventing osteoporosis.展开更多
Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials prov...Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials provide a promising prospect for imaging-guided precision therapy.Considering that tumor-derived alkaline phosphatase(ALP)is over-expressed in metastatic PCa,it makes a great chance to develop a theranostics system with ALP responsive in the TME.Herein,an ALP-responsive aggregationinduced emission luminogens(AIEgens)nanoprobe AMNF self-assembly was designed for enhancing the diagnosis and treatment of metastatic PCa.The nanoprobe exhibited self-aggregation in the presence of ALP resulted in aggregation-induced fluorescence,and enhanced accumulation and prolonged retention period at the tumor site.In terms of detection,the fluorescence(FL)/computed tomography(CT)/magnetic resonance(MR)multi-mode imaging effect of nanoprobe was significantly improved post-aggregation,enabling precise diagnosis through the amalgamation of multiple imaging modes.Enhanced CT/MR imaging can achieve assist preoperative tumor diagnosis,and enhanced FL imaging technology can achieve“intraoperative visual navigation”,showing its potential application value in clinical tumor detection and surgical guidance.In terms of treatment,AMNF showed strong absorption in the near infrared region after aggregation,which improved the photothermal treatment effect.Overall,our work developed an effective aggregation-enhanced theranostic strategy for ALP-related cancers.展开更多
The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this stu...The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.展开更多
The dominant wavelength range of edge impurity emissions moves from the visible range to the vacuum ultraviolet(VUV)range,as heating power increasing in the Experimental Advanced Superconducting Tokamak(EAST).The meas...The dominant wavelength range of edge impurity emissions moves from the visible range to the vacuum ultraviolet(VUV)range,as heating power increasing in the Experimental Advanced Superconducting Tokamak(EAST).The measurement provided by the existing visible spectroscopies in EAST is not sufficient for impurity transport studies for high-parameters plasmas.Therefore,in this study,a VUV spectroscopy is newly developed to measure edge impurity emissions in EAST.One Seya-Namioka VUV spectrometer(McPherson 234/302)is used in the system,equipped with a concave-corrected holographic grating with groove density of 600 grooves mm-1.Impurity line emissions can be observed in the wavelength range ofλ=50-700 nm,covering VUV,near ultraviolet and visible ranges.The observed vertical range is Z=-350-350 mm.The minimum sampling time can be set to 5 ms under full vertical binning(FVB)mode.VUV spectroscopy has been used to measure the edge impurity emission for the 2019 EAST experimental campaign.Impurity spectra are identified for several impurity species,i.e.,lithium(Li),carbon(C),oxygen(O),and iron(Fe).Several candidates for tungsten(W)lines are also measured but their clear identification is very difficult due to a strong overlap with Fe lines.Time evolutions of impurity carbon emissions of CⅡat 134.5 nm and CⅢat 97.7 nm are analyzed to prove the system capability of time-resolved measurement.The measurements of the VUV spectroscopy are very helpful for edge impurity transport study in the high-parameters plasma in EAST.展开更多
The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the fi...The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the first time our research determined that the nanofiber electrodes were restricted by the poor chemical stability of the polymer carriers.To gain further insight into the durability of nanofiber electrodes,both cyclic voltammetry aging tests and Fenton’s tests were conducted.Similar to previous reports,our research demonstrated that nanofiber electrodes showed remarkable stability in the cyclic voltammetry aging process.However,Fenton’s tests indicated that nanofibers in the electrodes would decompose easily while being attacked by reactive oxygen species such as HO·or HOO·,which greatly limits their practicability and reliability.The different performances under the two tests also demonstrated that the cyclic voltammetry aging protocols,which have been applied extensively,cannot well mirror the real operating conditions of fuel cells.展开更多
Solid oxide fuel cells(SOFCs)have attracted a great deal of interest because they have the highest efficiency without using any noble metal as catalysts among all the fuel cell technologies.However,traditional SOFCs s...Solid oxide fuel cells(SOFCs)have attracted a great deal of interest because they have the highest efficiency without using any noble metal as catalysts among all the fuel cell technologies.However,traditional SOFCs suffer from having a higher volume,current leakage,complex connections,and difficulty in gas sealing.To solve these problems,Rolls-Royce has fabricated a simple design by stacking cells in series on an insulating porous support,resulting in the tubular segmented-in-series solid oxide fuel cells(SIS-SOFCs),which achieved higher output voltage.This work systematically reviews recent advances in the structures,preparation methods,perform-ances,and stability of tubular SIS-SOFCs in experimental and numerical studies.Finally,the challenges and future development of tubular SIS-SOFCs are also discussed.The findings of this work can help guide the direction and inspire innovation of future development in this field.展开更多
AlGaN/GaN heterojunction field-effect transistors(HFETs)with p-GaN cap layer are developed for normally-off operation,in which an in-situ grown AlN layer is utilized as the gate insulator.Compared with the SiNxgate in...AlGaN/GaN heterojunction field-effect transistors(HFETs)with p-GaN cap layer are developed for normally-off operation,in which an in-situ grown AlN layer is utilized as the gate insulator.Compared with the SiNxgate insulator,the AlN/p-GaN interface presents a more obvious energy band bending and a wider depletion region,which helps to positively shift the threshold voltage.In addition,the relatively large conduction band offset of AlN/p-GaN is beneficial to suppress the gate leakage current and enhance the gate breakdown voltage.Owing to the introduction of AlN layer,normally-off p-GaN capped AlGaN/GaN HFET with a threshold voltage of 4 V and a gate swing of 13 V is realized.Furthermore,the field-effect mobility is approximately 1500 cm^(2)·V^(-1)·s^(-1)in the 2DEG channel,implying a good device performance.展开更多
Conducting polymers have achieved remarkable attentions owing to their exclusive characteristics,for instance,electrical conductivity,high ionic conductivity,visual transparency,and mechanical tractability.Surface and...Conducting polymers have achieved remarkable attentions owing to their exclusive characteristics,for instance,electrical conductivity,high ionic conductivity,visual transparency,and mechanical tractability.Surface and nanostructure engineering of conjugated conducting polymers offers an exceptional pathway to facilitate their implementation in a variety of scientific claims,comprising energy storage and production devices,flexible and wearable optoelectronic devices.A two-step tactic to assemble high-performance polypyrrole(PPy)-based microsupercapacitor(MSC)is utilized by transforming the current collectors to suppress structural pulverization and increase the adhesion of PPy,and then electrochemical co-deposition of PPy-CNT nanostructures on rGO@Au current collectors is performed.The resulting fine patterned MSC conveyed a high areal capacitance of 65.9 mF cm^(−2)(at a current density of 0.1 mA cm^(−2)),an exceptional cycling performance of retaining 79%capacitance after 10,000 charge/discharge cycles at 5 mA cm^(−2).Benefiting from the intermediate graphene,current collector free PPy-CNT@rGO flexible MSC is produced by a facile transfer method on a flexible substrate,which delivered an areal capacitance of 70.25 mF cm^(−2) at 0.1 mA cm^(−2) and retained 46%of the initial capacitance at a current density of 1.0 mA cm^(−2).The flexible MSC is utilized as a skin compatible capacitive micro-strain sensor with excellent electromechanochemical characteristics.展开更多
A novel and practical synthetic route is presented for the preparation of methyl-（E）-2-（3-（3-（2-（7-chloro-2-quinolinyl）ethenyl） phenyl）-3-oxopropyl）benzoate,the key intermediate of Montelukast,a leukotriene ...A novel and practical synthetic route is presented for the preparation of methyl-（E）-2-（3-（3-（2-（7-chloro-2-quinolinyl）ethenyl） phenyl）-3-oxopropyl）benzoate,the key intermediate of Montelukast,a leukotriene antagonist.The main diarylpropane framework was prepared via a polarity conversation reaction resulting in an acyl anion equivalent followed by a nucleophilic substitution reaction.The overall yield of this approach was 61%.This method is simple for operation and suitable for industrial production.展开更多
High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinde...High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinder its practicability.Herein we propose one-prong generic strategy to boost the cycling stability of PPy.For our strategy,the electrochemical deposition of multilayered reduced graphene oxide(rGO)on micropatterned Au is utilized,and the resultant rGO@Au pattern is then used for growing highly porous PPy nanostructures by facile electrochemical polymerization.The fabricated PPy anode on rGO@Au has quasi rectangular cyclic voltammetry curves up to-0.7 V and exceptional cycling stability,retaining82%of capacitance after 10,000 charge/discharge cycles in 2 M KCl electrolyte.The outstanding reliability of PPy on rGO@Au is due to the flexibility of rGO,accommodating structural pulverization and providing a promising background for the nucleation of highly porous nanostructure.Further,an all-polymer based asymmetric aqueous MSC(AMSC)is constructed with PPy anode and PEDOT cathode,which exhibited excellent electrochemical performance compared with conventional symmetric MSCs based on conducting polymers.The constructed AMSC delivered a maximum areal capacitance of 15.9 m F cm^-2(99.3 F cm^-3),high specific energy and power densities of 4.3μWh cm^-2(27.03 mWh cm^-3)and 0.36 W cm^-2(0.68 W cm^-3)at 1.4 V,respectively.The enhanced electrochemical performances can be illustrated by nucleation mechanism,in which surface topology of r GO generates a promising background for nucleation and electrochemical growth of nanoporous pseudocapacitive conducting polymers with superior interfacial contact and improved surface area.展开更多
The effect of high overdrive voltage on the positive bias temperature instability(PBTI)trapping behavior is investigated for GaN metal–insulator–semiconductor high electron mobility transistor(MIS-HEMT)with LPCVD-Si...The effect of high overdrive voltage on the positive bias temperature instability(PBTI)trapping behavior is investigated for GaN metal–insulator–semiconductor high electron mobility transistor(MIS-HEMT)with LPCVD-SiNx gate dielectric.A higher overdrive voltage is more effective to accelerate the electrons trapping process,resulting in a unique trapping behavior,i.e.,a larger threshold voltage shift with a weaker time dependence and a weaker temperature dependence.Combining the degradation of electrical parameters with the frequency–conductance measurements,the unique trapping behavior is ascribed to the defect energy profile inside the gate dielectric changing with stress time,new interface/border traps with a broad distribution above the channel Fermi level are introduced by high overdrive voltage.展开更多
Nighttime sap flow(Q_(n))is an important physiological activity under which trees manage drought stress.An in-depth understanding of the characteristics of Q_(n)and its response to environmental and canopy conditions ...Nighttime sap flow(Q_(n))is an important physiological activity under which trees manage drought stress.An in-depth understanding of the characteristics of Q_(n)and its response to environmental and canopy conditions are of significance for arid area forest and water management.This study measured daily sap flow(Q_(s))of a Larix principis-rupprechtii plantation in the Liupan Mountains,northwest China during the 2017-2019 growing seasons,and separated Q_(s)into daytime sap flow(Qd)and Q_(n).Meteorological conditions(reference evapotranspiration,ETref),canopy structure(leaf area index,LAI),and soil moisture(relative soil water content,RSWC)were considered as the main biophysical factors affecting Q_(n).The structural equation model and upper boundary line method determined the effects of compound and single factors on Q_(n)The daily mean Q_(n)values during the growing seasons in 2017,2018,and 2019 were 0.024,0.026,and 0.030 mm d-1,accounting for 6.2,11.2,and 10.1%of Q_(s),respectively.Q_(n)at different canopy development phases(leaf expanding,LG;leaf expanded,LD;and defoliation,DF)over three years was LD>LG>DF.Q_(n)increased with increasing ETref,whereas the ratio of Q_(n)to Q_(s)decreased.Q_(n)did not show regular variation in the three-year growing seasons under different soil moisture conditions.ETrefand LAI mainly controlled Q_(n)by affecting Qd,whereas RSWC had no significant effect on Q_(n).Q_(n)had a positive and linear relationship with LAI and a quadratic relationship with ETref.Both explained 40%of variation in Q_(n)Meteorological and canopy conditions are important factors affecting Q_(n)on the semi-humid study site.The application of the Q_(n)model coupled with the impact of ETrefand LAI furthers understanding of the impacts of climate and forest structure change on Q_(n).展开更多
Stress voltages on time-dependent breakdown characteristics of GaN MIS-HEMTs during negative gate bias stress (with VGS < 0, VD = VS = 0) and off-state stress (VG < VTh, VDS > 0, VS = 0) are investigated. For...Stress voltages on time-dependent breakdown characteristics of GaN MIS-HEMTs during negative gate bias stress (with VGS < 0, VD = VS = 0) and off-state stress (VG < VTh, VDS > 0, VS = 0) are investigated. For negative bias stress, the breakdown time distribution (β) decreases with the increasing negative gate voltage, while β is larger for higher drain voltage at off-state stress. Two humps in the time-dependent gate leakage occurred under both breakdown conditions, which can be ascribed to the dielectric breakdown triggered earlier and followed by the GaN layer breakdown. Combining the electric distribution from simulation and long-term monitoring of electric parameter, the peak electric fields under the gate edges at source and drain sides are confirmed as the main formation locations for per-location paths during negative gate voltage stress and off-state stress, respectively.展开更多
BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes ...BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.展开更多
Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configura...Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configuration transformation is prominent feature of the metamorphic mechanism. The number of constraints or properties of the kinematic pairs provided by the metamorphic kinematic pairs will change under certain conditions, its dynamic performance is much more complex than that of traditional kinematic pairs with immutable constraints. However, the clearance model about traditional kinematic pairs with immutable constraints established by long-term research is difficult to be directly applied to the metachromatic kinematic pairs. Referring to the experience of the traditional kinematic pairs with immutable constraints, the continuous contact model of Metamorphic Groove pin pair with clearance is established. According to the traditional continuous contact model of the kinematic pairs with immutable constraints, the forces between the elements of kinematic pair of the mechanism with clearance and the ideal mechanism without clearance are regarded as the same, and the inertia force and inertia moment of the components are also calculated according to the acceleration of the ideal mechanism. The clearance is regarded as a massless virtual bar with length r. For the rotating pair part, the massless virtual bar length r is the difference between the radius of the shaft and the hole, and for the sliding pair part, the massless virtual bar length r is half of the difference between the height of the slider and the guide groove. According to the new mechanism without gap after adding the imaginary bar, kinetic energy and potential energy of the system are calculated for the two configurations of mechanism with metamorphic Groove pin pair with clearance. The kinetic energy and potential energy of the system are calculated according to the new mechanism without clearance after adding the massless virtual bar. The kinetic energy, potential energy and generalized force are substituted into the Lagrangian equation to obtain the motion equation of the metamorphic mechanism, which lays the foundation for the dynamic performance study of the mechanism with metamorphic groove pin pair with clearance.展开更多
Objective:This prospective randomized controlled study was conducted to evaluate the safety and efficacy of the Pringle hepatic hilar occlusion with a bulldog clamp in laparoscopic liver resection.Methods:From March 1...Objective:This prospective randomized controlled study was conducted to evaluate the safety and efficacy of the Pringle hepatic hilar occlusion with a bulldog clamp in laparoscopic liver resection.Methods:From March 1,2020 to July 31,2021,80 patients were enrolled,including 40 undergoing intraperitoneal Pringle maneuver(IPM)and 40 extraperitoneal Pringle maneuver(EPM).The observation indices included basic preoperative clinical characteristics and intraoperative and postoperative liver function indices.Results:There were no significant differences in the basic characteristics or types of hepatectomy,intraoperative blood loss,intraoperative blood transfusion,or hepatectomy time between the IPM and EPM groups.However,the blocking and operation time in the IPM group was shorter than that in the EPM group.There were no significant differences in alanine aminotransferase(ALT)or aspartate aminotransferase(AST)levels on the first day after surgery or in total bilirubin(TBIL)or albumin(ALB)levels on the first,third,or fifth days after surgery.However,C-reactive protein(CRP)levels on the first and third days,ALT and AST levels on the third and fifth days were lower,and hospital stay after surgery was shorter in the IPM group than in the EPM group.Conclusion:IPM using bulldog clamps is simple,safe,and effective.The inflammatory reaction is less severe,the degree of liver function injury is lower,and recovery is faster.展开更多
High-entropy alloys(HEAs)have attracted widespread attention due to their excellent mechanical properties.However,their functional properties arising from the supersaturated solid solution state can be improved.Advanc...High-entropy alloys(HEAs)have attracted widespread attention due to their excellent mechanical properties.However,their functional properties arising from the supersaturated solid solution state can be improved.Advanced oxidation processes(AOPs)are considered to be an effective method for decomposing organic pollutants,and HEAs are proposed as effective candidates for AOP catalysts.Currently,several HEAs used for organic pollutant degradation are prepared through mechanical alloying.In this work,FeAlCoNi and FeAlCoNiB Fenton-like catalysts were prepared by single roll melt spinning and subsequent ball milling techniques.We found that the FeAlCoNiB HEA exhibits highly efficient degradation for p-nitrophenol(p-NP).The degradation efficiency of FeAlCoNiB is 120 times higher than that of FeAlCoNi,which confirms that boron functions effectively during the degradation process.FeAlCoNiB has a better degradation efficiency than pure iron powder and a degradation efficiency comparable to that of the amorphous Fe_(78)Si_(11)B_(11) alloy.Additionally,the degradation efficiency of FeAlCoNiB_(X) increases(k values from 0.13 to 0.55 min^(−1))when the boron content increases from an X value of 0.25 to 1.25.We speculate that Fe_(2)B favors the degradation process and promotes zero-valent iron to decompose organic pollutants through a galvanic cell effect.Possible p-NP degradation pathways are proposed after LC–MS analysis.This study provides a new series of HEA Fenton-like catalysts,which have the potential to be prepared into bulk devices for industrial applications.展开更多
High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is ...High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film capacitor.In this work,a novel high-temperature-resistant dielectric film was prepared.Firstly,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the materials.Compared with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at break.The dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 kHz.Moreover,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.展开更多
The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrod...The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrode technique and the slow strain rate test (SSRT). Results of the static corrosion tests and corrosion morphology show that the prior austenite grain boundaries and martensite lath boundaries are the preferred sites for pit nucleation and growth in chloride environment. Results of SSRT coupled with insitu electrochemical test show that the transition from pitting corrosion to uniform corrosion, as well as the nucleation of stress corrosion crack, is the synergistic effects of the chloride and applied load. Stress corrosion cracking of the steel in the chloride environment can be divided into three different regions as follows: fast and uniform corrosion activ-ity, microcrack nucleation and propagation, and active crack growth regions.展开更多
基金National Key Research and Development Program of China(2023YFB3810200 to J.L.)National Natural Science Foundation of China(92168204,82225030 to J.L.)Fundamental Research Funds for the Central Universities(22120210586 to J.L.)。
文摘Reproductive hormones associated with the hypothalamic-pituitary-gonadal(HPG)axis are closely linked to bone homeostasis.In this study,we demonstrate that Gonadotropin inhibitory hormone(GnIH,one of the key reproductive hormones upstream of the HPG axis)plays an indispensable role in regulating bone homeostasis and maintaining bone mass.We find that deficiency of GnIH or its receptor Gpr147 leads to a significant reduction in bone mineral density(BMD)in mice primarily by enhancement of osteoclast activation in vivo and in vitro.Mechanistically,GnIH/Gpr147 inhibits osteoclastogenesis by the PI3K/AKT,MAPK,NF-κB and Nfatc1 signaling pathways.Furthermore,GnIH treatment was able to alleviate bone loss in aging,ovariectomy(OVX)or LPS-induced mice.Moreover,the therapy using green light promotes the release of GnIH and rescues OVX-induced bone loss.In humans,serum GnIH increases and bone resorption markers decrease after green light exposure.Therefore,our study elucidates that GnIH plays an important role in maintaining bone homeostasis via modulating osteoclast differentiation and demonstrates the potential of GnIH therapy or green light therapy in preventing osteoporosis.
基金supported by Natural Science Foundation of Jilin Province(No.SKL202302002)Key Research and Development project of Jilin Provincial Science and Technology Department(No.20210204142YY)+2 种基金The Science and Technology Development Program of Jilin Province(No.2020122256JC)Beijing Kechuang Medical Development Foundation Fund of China(No.KC2023-JX-0186BQ079)Talent Reserve Program(TRP),the First Hospital of Jilin University(No.JDYY-TRP-2024007)。
文摘Prostate cancer(PCa)is characterized by high incidence and propensity for easy metastasis,presenting significant challenges in clinical diagnosis and treatment.Tumor microenvironment(TME)-responsive nanomaterials provide a promising prospect for imaging-guided precision therapy.Considering that tumor-derived alkaline phosphatase(ALP)is over-expressed in metastatic PCa,it makes a great chance to develop a theranostics system with ALP responsive in the TME.Herein,an ALP-responsive aggregationinduced emission luminogens(AIEgens)nanoprobe AMNF self-assembly was designed for enhancing the diagnosis and treatment of metastatic PCa.The nanoprobe exhibited self-aggregation in the presence of ALP resulted in aggregation-induced fluorescence,and enhanced accumulation and prolonged retention period at the tumor site.In terms of detection,the fluorescence(FL)/computed tomography(CT)/magnetic resonance(MR)multi-mode imaging effect of nanoprobe was significantly improved post-aggregation,enabling precise diagnosis through the amalgamation of multiple imaging modes.Enhanced CT/MR imaging can achieve assist preoperative tumor diagnosis,and enhanced FL imaging technology can achieve“intraoperative visual navigation”,showing its potential application value in clinical tumor detection and surgical guidance.In terms of treatment,AMNF showed strong absorption in the near infrared region after aggregation,which improved the photothermal treatment effect.Overall,our work developed an effective aggregation-enhanced theranostic strategy for ALP-related cancers.
基金financially supported by the National Key Research and Development Program of China (Grant no.2016YFB0101208)NSFC-Liaoning Joint Funding (Grant no. U1508202)the National Natural Science Foundations of China (Grant no. 61433013 and 91434131)
文摘The electrode Pt-loading has an effect on the number of active sites and the thickness of catalyst layer,which has huge influence on the mass transfer and water management during dynamic process in PEMFCs. In this study, membrane electrode assemblies with different Pt-loadings were prepared, and PEMFCs were assembled using those membrane electrode assemblies with traditional solid plate and water transport plate as cathode flow-field plates, respectively. The performance and electrochemical surface area of cells were characterized to evaluate the membrane electrode assemblies degradation after rapid currentvariation cycles. Scanning electron microscope and transmission electron microscope were used to investigate the decay of catalyst layers and Pt/C catalyst. With the increase of Pt-loading, the performance degradation of membrane electrode assemblies will be mitigated. But higher Pt-loading means thicker catalyst layer, which leads to a longer pathway of mass transfer, and it may result in carbon material corrosion in membrane electrode assemblies. The decay of Pt/C catalyst in cathode is mainly caused by the corrosion of carbon support, and the degradation of anode Pt/C catalyst is a consequence of migration and aggregation of Pt particles. And using water transport plate is beneficial to alleviating the age of cathode Pt/C catalyst.
基金the National Magnetic Confinement Fusion Science Program of China(Nos.2017YFE0301300 and 2018YFE0301100)National Natural Science Foundation of China(Nos.11805231,11705151)+4 种基金ASIPP Science and Research Grant(No.DSJJ-17-03)Key Program of Research and Development of Hefei Science Center(No.2017HSC-KPRD002)Anhui Provincial Natural Sci-ence Foundation(Nos.1808085QA14 and 1908085J01)Instrument Developing Project of the Chinese Academy of Sciences(No.YJKYYQ20180013)Collaborative Innovation Program of Hefei Science Center,CAS(No.2019HSC-CIP005).
文摘The dominant wavelength range of edge impurity emissions moves from the visible range to the vacuum ultraviolet(VUV)range,as heating power increasing in the Experimental Advanced Superconducting Tokamak(EAST).The measurement provided by the existing visible spectroscopies in EAST is not sufficient for impurity transport studies for high-parameters plasmas.Therefore,in this study,a VUV spectroscopy is newly developed to measure edge impurity emissions in EAST.One Seya-Namioka VUV spectrometer(McPherson 234/302)is used in the system,equipped with a concave-corrected holographic grating with groove density of 600 grooves mm-1.Impurity line emissions can be observed in the wavelength range ofλ=50-700 nm,covering VUV,near ultraviolet and visible ranges.The observed vertical range is Z=-350-350 mm.The minimum sampling time can be set to 5 ms under full vertical binning(FVB)mode.VUV spectroscopy has been used to measure the edge impurity emission for the 2019 EAST experimental campaign.Impurity spectra are identified for several impurity species,i.e.,lithium(Li),carbon(C),oxygen(O),and iron(Fe).Several candidates for tungsten(W)lines are also measured but their clear identification is very difficult due to a strong overlap with Fe lines.Time evolutions of impurity carbon emissions of CⅡat 134.5 nm and CⅢat 97.7 nm are analyzed to prove the system capability of time-resolved measurement.The measurements of the VUV spectroscopy are very helpful for edge impurity transport study in the high-parameters plasma in EAST.
基金National Key Point Research and Invention Program of the Thirteenth(Program Nos.2018YFB0105601 and 2017YFB0102801).
文摘The nanofiber electrodes have been considered as promising candidates for commercial proton exchange membrane fuel cells due to their high catalyst utilization and enhanced mass transport efficiency.However,for the first time our research determined that the nanofiber electrodes were restricted by the poor chemical stability of the polymer carriers.To gain further insight into the durability of nanofiber electrodes,both cyclic voltammetry aging tests and Fenton’s tests were conducted.Similar to previous reports,our research demonstrated that nanofiber electrodes showed remarkable stability in the cyclic voltammetry aging process.However,Fenton’s tests indicated that nanofibers in the electrodes would decompose easily while being attacked by reactive oxygen species such as HO·or HOO·,which greatly limits their practicability and reliability.The different performances under the two tests also demonstrated that the cyclic voltammetry aging protocols,which have been applied extensively,cannot well mirror the real operating conditions of fuel cells.
基金supported by the National Natural Science Foundation of China(Nos.21701083 and 22179054).
文摘Solid oxide fuel cells(SOFCs)have attracted a great deal of interest because they have the highest efficiency without using any noble metal as catalysts among all the fuel cell technologies.However,traditional SOFCs suffer from having a higher volume,current leakage,complex connections,and difficulty in gas sealing.To solve these problems,Rolls-Royce has fabricated a simple design by stacking cells in series on an insulating porous support,resulting in the tubular segmented-in-series solid oxide fuel cells(SIS-SOFCs),which achieved higher output voltage.This work systematically reviews recent advances in the structures,preparation methods,perform-ances,and stability of tubular SIS-SOFCs in experimental and numerical studies.Finally,the challenges and future development of tubular SIS-SOFCs are also discussed.The findings of this work can help guide the direction and inspire innovation of future development in this field.
基金Supported by the National Natural Science Foundation of China(Grant No.61904207)scientific research support foundation for introduced high-level talents of Shenyang Ligong University(Grant No.1010147000914)the Natural Science Foundation of Sichuan Province,China(Grant No.2022NSFSC0886)
文摘AlGaN/GaN heterojunction field-effect transistors(HFETs)with p-GaN cap layer are developed for normally-off operation,in which an in-situ grown AlN layer is utilized as the gate insulator.Compared with the SiNxgate insulator,the AlN/p-GaN interface presents a more obvious energy band bending and a wider depletion region,which helps to positively shift the threshold voltage.In addition,the relatively large conduction band offset of AlN/p-GaN is beneficial to suppress the gate leakage current and enhance the gate breakdown voltage.Owing to the introduction of AlN layer,normally-off p-GaN capped AlGaN/GaN HFET with a threshold voltage of 4 V and a gate swing of 13 V is realized.Furthermore,the field-effect mobility is approximately 1500 cm^(2)·V^(-1)·s^(-1)in the 2DEG channel,implying a good device performance.
基金support of the National Key R&D Program of China(Grant No.2021YFB3200701,2018YFA0208501)the National Natural Science Foundation of China(Grant No.52272098,21875260,21671193,91963212,51773206,21731001,22272182)Beijing Natural Science Foundation(No.2202069).
文摘Conducting polymers have achieved remarkable attentions owing to their exclusive characteristics,for instance,electrical conductivity,high ionic conductivity,visual transparency,and mechanical tractability.Surface and nanostructure engineering of conjugated conducting polymers offers an exceptional pathway to facilitate their implementation in a variety of scientific claims,comprising energy storage and production devices,flexible and wearable optoelectronic devices.A two-step tactic to assemble high-performance polypyrrole(PPy)-based microsupercapacitor(MSC)is utilized by transforming the current collectors to suppress structural pulverization and increase the adhesion of PPy,and then electrochemical co-deposition of PPy-CNT nanostructures on rGO@Au current collectors is performed.The resulting fine patterned MSC conveyed a high areal capacitance of 65.9 mF cm^(−2)(at a current density of 0.1 mA cm^(−2)),an exceptional cycling performance of retaining 79%capacitance after 10,000 charge/discharge cycles at 5 mA cm^(−2).Benefiting from the intermediate graphene,current collector free PPy-CNT@rGO flexible MSC is produced by a facile transfer method on a flexible substrate,which delivered an areal capacitance of 70.25 mF cm^(−2) at 0.1 mA cm^(−2) and retained 46%of the initial capacitance at a current density of 1.0 mA cm^(−2).The flexible MSC is utilized as a skin compatible capacitive micro-strain sensor with excellent electromechanochemical characteristics.
基金supported by the National Key Project for Basic Research(No2010CB1126102)the Outstanding Youth Foundation of Heilongjiang Province(NoJC200706)
文摘A novel and practical synthetic route is presented for the preparation of methyl-（E）-2-（3-（3-（2-（7-chloro-2-quinolinyl）ethenyl） phenyl）-3-oxopropyl）benzoate,the key intermediate of Montelukast,a leukotriene antagonist.The main diarylpropane framework was prepared via a polarity conversation reaction resulting in an acyl anion equivalent followed by a nucleophilic substitution reaction.The overall yield of this approach was 61%.This method is simple for operation and suitable for industrial production.
基金supported by the National Natural Science Fund for Distinguished Young Scholars(51425204)the National Natural Science Foundation of China(51521001)+2 种基金the National Key Research and Development Program of China(2016YFA0202603,2016YFA0202604)the Programme of Introducing Talents of Discipline to Universities(B17034)the Yellow Crane Talent(Science&Technology)Program of Wuhan City。
文摘High-performance anode is hurdle for on-chip planar microsupercapacitor(MSC).Polypyrrole(PPy)is a highly attractive pseudocapacitive material,but its low cycling stability,and low adhesion with current collector hinder its practicability.Herein we propose one-prong generic strategy to boost the cycling stability of PPy.For our strategy,the electrochemical deposition of multilayered reduced graphene oxide(rGO)on micropatterned Au is utilized,and the resultant rGO@Au pattern is then used for growing highly porous PPy nanostructures by facile electrochemical polymerization.The fabricated PPy anode on rGO@Au has quasi rectangular cyclic voltammetry curves up to-0.7 V and exceptional cycling stability,retaining82%of capacitance after 10,000 charge/discharge cycles in 2 M KCl electrolyte.The outstanding reliability of PPy on rGO@Au is due to the flexibility of rGO,accommodating structural pulverization and providing a promising background for the nucleation of highly porous nanostructure.Further,an all-polymer based asymmetric aqueous MSC(AMSC)is constructed with PPy anode and PEDOT cathode,which exhibited excellent electrochemical performance compared with conventional symmetric MSCs based on conducting polymers.The constructed AMSC delivered a maximum areal capacitance of 15.9 m F cm^-2(99.3 F cm^-3),high specific energy and power densities of 4.3μWh cm^-2(27.03 mWh cm^-3)and 0.36 W cm^-2(0.68 W cm^-3)at 1.4 V,respectively.The enhanced electrochemical performances can be illustrated by nucleation mechanism,in which surface topology of r GO generates a promising background for nucleation and electrochemical growth of nanoporous pseudocapacitive conducting polymers with superior interfacial contact and improved surface area.
基金Project supported by the National Key Research and Development Program,China(Grant No.2017YFB0402800)the Key Research and Development Program of Guangdong Province,China(Grant No.2019B010128002)+1 种基金the National Natural Science Foundation of China(Grant No.U1601210)the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030312011)。
文摘The effect of high overdrive voltage on the positive bias temperature instability(PBTI)trapping behavior is investigated for GaN metal–insulator–semiconductor high electron mobility transistor(MIS-HEMT)with LPCVD-SiNx gate dielectric.A higher overdrive voltage is more effective to accelerate the electrons trapping process,resulting in a unique trapping behavior,i.e.,a larger threshold voltage shift with a weaker time dependence and a weaker temperature dependence.Combining the degradation of electrical parameters with the frequency–conductance measurements,the unique trapping behavior is ascribed to the defect energy profile inside the gate dielectric changing with stress time,new interface/border traps with a broad distribution above the channel Fermi level are introduced by high overdrive voltage.
基金funded by the National Natural Science Foundation of China(41971038U20A2085+3 种基金32171559U21A2005)the Fundamental Research Funds of CAF(CAFYBB2020QB004CAFYBB2021ZW002)。
文摘Nighttime sap flow(Q_(n))is an important physiological activity under which trees manage drought stress.An in-depth understanding of the characteristics of Q_(n)and its response to environmental and canopy conditions are of significance for arid area forest and water management.This study measured daily sap flow(Q_(s))of a Larix principis-rupprechtii plantation in the Liupan Mountains,northwest China during the 2017-2019 growing seasons,and separated Q_(s)into daytime sap flow(Qd)and Q_(n).Meteorological conditions(reference evapotranspiration,ETref),canopy structure(leaf area index,LAI),and soil moisture(relative soil water content,RSWC)were considered as the main biophysical factors affecting Q_(n).The structural equation model and upper boundary line method determined the effects of compound and single factors on Q_(n)The daily mean Q_(n)values during the growing seasons in 2017,2018,and 2019 were 0.024,0.026,and 0.030 mm d-1,accounting for 6.2,11.2,and 10.1%of Q_(s),respectively.Q_(n)at different canopy development phases(leaf expanding,LG;leaf expanded,LD;and defoliation,DF)over three years was LD>LG>DF.Q_(n)increased with increasing ETref,whereas the ratio of Q_(n)to Q_(s)decreased.Q_(n)did not show regular variation in the three-year growing seasons under different soil moisture conditions.ETrefand LAI mainly controlled Q_(n)by affecting Qd,whereas RSWC had no significant effect on Q_(n).Q_(n)had a positive and linear relationship with LAI and a quadratic relationship with ETref.Both explained 40%of variation in Q_(n)Meteorological and canopy conditions are important factors affecting Q_(n)on the semi-humid study site.The application of the Q_(n)model coupled with the impact of ETrefand LAI furthers understanding of the impacts of climate and forest structure change on Q_(n).
基金Project supported by the National Key Research and Development Program,China(Grant No.2017YFB0402800)the Key Research and Development Program of Guangdong Province,China(Grant Nos.2019B010128002 and 2020B010173001)+4 种基金the National Natural Science Foundation of China(Grant No.U1601210)the Natural Science Foundation of Guangdong Province,China(Grant No.2015A030312011)the Open Project of Key Laboratory of Microelectronic Devices and Integrated Technology(Grant No.202006)the Science and Technology Plan of Guangdong Province,China(Grant No.2017B010112002)the China Postdoctoral Science Foundation(Grant No.2019M663233).
文摘Stress voltages on time-dependent breakdown characteristics of GaN MIS-HEMTs during negative gate bias stress (with VGS < 0, VD = VS = 0) and off-state stress (VG < VTh, VDS > 0, VS = 0) are investigated. For negative bias stress, the breakdown time distribution (β) decreases with the increasing negative gate voltage, while β is larger for higher drain voltage at off-state stress. Two humps in the time-dependent gate leakage occurred under both breakdown conditions, which can be ascribed to the dielectric breakdown triggered earlier and followed by the GaN layer breakdown. Combining the electric distribution from simulation and long-term monitoring of electric parameter, the peak electric fields under the gate edges at source and drain sides are confirmed as the main formation locations for per-location paths during negative gate voltage stress and off-state stress, respectively.
文摘BACKGROUND In patients with schizophrenia,the brain structure and neurotransmitter levels change,which may be related to the occurrence and progression of this disease.AIM To explore the relationships between changes in neurotransmitters,brain structural characteristics,and the scores of the Positive and Negative Symptom Scale(PANSS)in patients with first-episode schizophrenia.METHODS The case group comprised 97 patients with schizophrenia,who were evaluated using the Canadian Neurological Scale and confirmed by laboratory tests at Ningbo Mental Hospital from January 2020 to July 2022.The control group comprised 100 healthy participants.For all participants,brain structural characteristics were explored by measuring brain dopamine(DA),glutamic acid(Glu),and gamma-aminobutyric acid(GABA)levels,with magnetic resonance imaging.The case group was divided into negative and positive symptom subgroups using PANSS scores for hierarchical analysis.Linear correlation analysis was used to analyze the correlations between neurotransmitters,brain structural character istics,and PANSS scores.RESULTS Patients in the case group had higher levels of DA and lower levels of Glu and GABA,greater vertical and horizontal distances between the corpus callosum and the inferior part of the fornix and larger ventricle area than patients in the control group(P<0.05).Patients with positive schizophrenia symptoms had significantly higher levels of DA,Glu,and GABA than those with negative symptoms(P<0.05).In patients with positive schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical and horizontal distances between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).In patients with negative schizophrenia symptoms,PANSS score was significantly positively correlated with DA,vertical distance between the corpus callosum and the infrafornix,horizontal distance between the corpus callosum and the infrafornix,and ventricular area,and was significantly negatively correlated with Glu and GABA(P<0.05).CONCLUSION In patients with first-episode schizophrenia,DA levels increased,Glu and GABA levels decreased,the thickness of the corpus callosum increased,and these variables were correlated with PANSS scores.
文摘Metamorphic mechanism has the advantages of variable topology and variable degrees of freedom, which can realize the requirements of multi-conditions and multi-tasks, and has a good application prospect. The configuration transformation is prominent feature of the metamorphic mechanism. The number of constraints or properties of the kinematic pairs provided by the metamorphic kinematic pairs will change under certain conditions, its dynamic performance is much more complex than that of traditional kinematic pairs with immutable constraints. However, the clearance model about traditional kinematic pairs with immutable constraints established by long-term research is difficult to be directly applied to the metachromatic kinematic pairs. Referring to the experience of the traditional kinematic pairs with immutable constraints, the continuous contact model of Metamorphic Groove pin pair with clearance is established. According to the traditional continuous contact model of the kinematic pairs with immutable constraints, the forces between the elements of kinematic pair of the mechanism with clearance and the ideal mechanism without clearance are regarded as the same, and the inertia force and inertia moment of the components are also calculated according to the acceleration of the ideal mechanism. The clearance is regarded as a massless virtual bar with length r. For the rotating pair part, the massless virtual bar length r is the difference between the radius of the shaft and the hole, and for the sliding pair part, the massless virtual bar length r is half of the difference between the height of the slider and the guide groove. According to the new mechanism without gap after adding the imaginary bar, kinetic energy and potential energy of the system are calculated for the two configurations of mechanism with metamorphic Groove pin pair with clearance. The kinetic energy and potential energy of the system are calculated according to the new mechanism without clearance after adding the massless virtual bar. The kinetic energy, potential energy and generalized force are substituted into the Lagrangian equation to obtain the motion equation of the metamorphic mechanism, which lays the foundation for the dynamic performance study of the mechanism with metamorphic groove pin pair with clearance.
基金supported by grants from Scientific Research Fund of Anhui Medical University(No.2021xkj034)Clinical Research Cultivation Program of the Second Affiliated Hospital of Anhui Medical University(No.2020LCYB18)Anhui Institute of Translational Medicine(No.2023zhyx-C84).
文摘Objective:This prospective randomized controlled study was conducted to evaluate the safety and efficacy of the Pringle hepatic hilar occlusion with a bulldog clamp in laparoscopic liver resection.Methods:From March 1,2020 to July 31,2021,80 patients were enrolled,including 40 undergoing intraperitoneal Pringle maneuver(IPM)and 40 extraperitoneal Pringle maneuver(EPM).The observation indices included basic preoperative clinical characteristics and intraoperative and postoperative liver function indices.Results:There were no significant differences in the basic characteristics or types of hepatectomy,intraoperative blood loss,intraoperative blood transfusion,or hepatectomy time between the IPM and EPM groups.However,the blocking and operation time in the IPM group was shorter than that in the EPM group.There were no significant differences in alanine aminotransferase(ALT)or aspartate aminotransferase(AST)levels on the first day after surgery or in total bilirubin(TBIL)or albumin(ALB)levels on the first,third,or fifth days after surgery.However,C-reactive protein(CRP)levels on the first and third days,ALT and AST levels on the third and fifth days were lower,and hospital stay after surgery was shorter in the IPM group than in the EPM group.Conclusion:IPM using bulldog clamps is simple,safe,and effective.The inflammatory reaction is less severe,the degree of liver function injury is lower,and recovery is faster.
基金financially supported by the Shenzhen Science and Technology Research Grant(No.20200812092703001).
文摘High-entropy alloys(HEAs)have attracted widespread attention due to their excellent mechanical properties.However,their functional properties arising from the supersaturated solid solution state can be improved.Advanced oxidation processes(AOPs)are considered to be an effective method for decomposing organic pollutants,and HEAs are proposed as effective candidates for AOP catalysts.Currently,several HEAs used for organic pollutant degradation are prepared through mechanical alloying.In this work,FeAlCoNi and FeAlCoNiB Fenton-like catalysts were prepared by single roll melt spinning and subsequent ball milling techniques.We found that the FeAlCoNiB HEA exhibits highly efficient degradation for p-nitrophenol(p-NP).The degradation efficiency of FeAlCoNiB is 120 times higher than that of FeAlCoNi,which confirms that boron functions effectively during the degradation process.FeAlCoNiB has a better degradation efficiency than pure iron powder and a degradation efficiency comparable to that of the amorphous Fe_(78)Si_(11)B_(11) alloy.Additionally,the degradation efficiency of FeAlCoNiB_(X) increases(k values from 0.13 to 0.55 min^(−1))when the boron content increases from an X value of 0.25 to 1.25.We speculate that Fe_(2)B favors the degradation process and promotes zero-valent iron to decompose organic pollutants through a galvanic cell effect.Possible p-NP degradation pathways are proposed after LC–MS analysis.This study provides a new series of HEA Fenton-like catalysts,which have the potential to be prepared into bulk devices for industrial applications.
基金financially supported by the National Natural Science Foundation of China(Nos.52073039,51903029,21805027,51803020 and 51773028)International Science and Technology Cooperation Project(No.52011530027)+3 种基金Major Special Projects of Sichuan Province(Nos.2020YFG0270,2020ZDZX0020,2019ZDZX0027 and 2019ZDZX0016)the Fundamental Research Funds for the Central Universities(No.ZYGX2019J026)Sichuan Science and Technology Program(Nos.2019YJ0197,2019YFG0056 and 2020YFG0100)International Science and Technology Cooperation Project from Chengdu municipal government(No.2019-GH02-00037-HZ)。
文摘High-quality film capacitors are widely used in many fields such as new energy vehicles,electronic communications,etc.,due to their advantages in wide frequency response and low dielectric loss.The dielectric film is a crucial part of the film capacitor,and its properties have an important impact on the performance and use conditions of the film capacitor.In this work,a novel high-temperature-resistant dielectric film was prepared.Firstly,the Bi_(2)S_(3)/rGO-CN fillers were prepared by hydrothermal method combined with cyanation treatment,and then added to the poly(arylene ether nitrile)(PEN)matrix to prepare the dielectric film materials(PEN/Bi_(2)S_(3)/rGO-CN).After high temperature treatment,the fillers Bi_(2)S_(3)/rGO-CN reacted with the PEN matrix,and the composites materials transformed into a thermosetting hybrid film(PEN-Bi_(2)S_(3)/rGO)with gel content of 97.88%.The prepared hybrid dielectric films did not decompose significantly before 400℃,and showed a glass transition temperature(Tg)of up to 252.4℃,which could increase the effective use temperature of the materials.Compared with the composite films without heat treatment,they exhibit better mechanical properties,with further improvement in tensile strength and elastic modulus,and a decrease in elongation at break.The dielectric constant of the hybrid films can be up to 6.8 while the dielectric loss is only about 0.02 at 1 kHz.Moreover,the hybrid films showed excellent dielectric stability during temperature changes,and remain relatively stable before 250℃,which is suitable as a high-temperature-resistant high-dielectric material and is more advantageous for practical applications.
文摘The electrochemical and stress corrosion cracking behavior of 9Cr ferritic-martensitic steel is investigated in the chloride environment by using the traditional electrochemical method, the scanning vibrating electrode technique and the slow strain rate test (SSRT). Results of the static corrosion tests and corrosion morphology show that the prior austenite grain boundaries and martensite lath boundaries are the preferred sites for pit nucleation and growth in chloride environment. Results of SSRT coupled with insitu electrochemical test show that the transition from pitting corrosion to uniform corrosion, as well as the nucleation of stress corrosion crack, is the synergistic effects of the chloride and applied load. Stress corrosion cracking of the steel in the chloride environment can be divided into three different regions as follows: fast and uniform corrosion activ-ity, microcrack nucleation and propagation, and active crack growth regions.
