The copper disc casting machine is core equipment for producing copper anode plates in the copper metallurgy industry.The copper disc casting machine casting package motion curve(CPMC) is significant for precise casti...The copper disc casting machine is core equipment for producing copper anode plates in the copper metallurgy industry.The copper disc casting machine casting package motion curve(CPMC) is significant for precise casting and efficient production.However,the lack of exact casting modeling and real-time simulation information severely restricts dynamic CPMC optimization.To this end,a liquid copper droplet model describes the casting package copper flow pattern in the casting process.Furthermore,a CPMC optimization model is proposed for the first time.On top of this,a digital twin dual closed-loop self-optimization application framework(DT-DCS) is constructed for optimizing the copper disc casting process to achieve self-optimization of the CPMC and closed-loop feedback of manufacturing information during the casting process.Finally,a case study is carried out based on the proposed methods in the industrial field.展开更多
Objective:To investigate current status of diagnosis and treatment of bladder cancer in China.Methods:A database was generated by Chinese Bladder Cancer Consortium(CBCC).From January 2007 to December 2012,14,260 cases...Objective:To investigate current status of diagnosis and treatment of bladder cancer in China.Methods:A database was generated by Chinese Bladder Cancer Consortium(CBCC).From January 2007 to December 2012,14,260 cases from 44 CBCC centers were included.Data of diagnosis,treatment and pathology were collected.Results:The average age was 63.5 year-old and most patients were male(84.3%).The most common histologic types were urothelial carcinoma(91.4%),adenocarcinoma(1.8%),and squamous carcinoma(1.9%).According to 1973 and 2004 WHO grading system,42.0%,41.0%,and 17.0% of patients were grade 1,2,and 3,and 16.0%,48.7%,and 35.3% of patients were papillary urothelial neoplasms of low malignant potential,low,and high grade,respectively.Non-muscle invasive bladder cancer(NMIBC)and muscle invasive bladder cancer(MIBC)were 25.2% and 74.1%,respectively(0.8% not clear).Carcinoma in situ was only 2.4%.Most patients were diagnosed by white-light cystoscopy with biopsy(74.3%).Fluorescence and narrow band imaging cystoscopy had additional detection rate of 1.0% and 4.0%,respectively.Diagnostic transurethral resection(TUR)provided detection rate of 16.9%.Most NMIBCs were treated with TUR(89.2%).After initial TUR,2.6%accepted second TUR,and 45.7%,69.9%,and 58.7% accepted immediate,induced,and maintenance chemotherapy instillation,respectively.Most MIBCs were treated with radical cystectomy(RC,59.7%).Laparoscopic RCs were 35.1%,while open RC 63.4%.Extended and standard pelvic lymph node dissection were 7% and 66%,respectively.Three most common urinary diversions were orthotopic neobladder(44%),ileal conduit(31%),and ureterocutaneostomy(23%).Only 2.3% of patients accepted neo-adjuvant chemotherapy and only 18%of T3 and T4 patients accepted adjuvant chemotherapy.Conclusion:Disease characteristics are similar to international reports,while differences of diagnosis and treatment exist.This study can provide evidences for revisions of the guideline on bladder cancer in China.展开更多
Hydrogen has been identified as one of the most promising sustainable and clean energy. Developing hydrogen evolution reaction(HER) catalyst with high activity is essential for satisfying the future requirements. Cons...Hydrogen has been identified as one of the most promising sustainable and clean energy. Developing hydrogen evolution reaction(HER) catalyst with high activity is essential for satisfying the future requirements. Considering novel advantages of two-dimensional materials and high catalytic activity of atomic transition metal, in this study, using density functional theory calculation, the HER on single transitionmetal(23 different TM atoms) doped phosphorus carbide monolayer(α-PC) has been investigated. The Volmer–Tafel and Volmer–Heyrovsky reaction mechanisms, and the stability of the most promising HER catalyst are also included. The results show that Ir-αPC with high physical and thermal stability has the most optimal value of Gibbs free adsorption energy for H atom. The relationship of d band center and the HER activity shows a volcano-like curve. The calculation of reaction energy barrier indicates that the Volmer-Heyrovsky step is more favorable than the Volmer-Tafel step.展开更多
Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer...Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer who underwent radical cystectomy(RC)in 13 centers of the Chinese Bladder Cancer Consortium(CBCC).Perioperative outcomes were compared between MIRC and ORC.The influence of surgical approaches on overall survival(OS)and cancer-specific survival(CSS)in the entire study group and subgroups classified according to pathologic stage or lymph node(LN)status was assessed with the log-rank test.Multivariable Cox proportional hazard models were used to evaluate the association among OS,CSS and risk factors of interest.Results:Of 2098 patients who underwent RC,1243 patients underwent MIRC(1087 laparoscopic RC and 156 robotic-assisted RC,respectively),while 855 patients underwent ORC.No significant differences were noted in positive surgical margin rate and 90-day postoperative mortality rate.MIRC was associated with less estimated blood loss,more LN yield,higher rate of neobladder diversion,longer operative time,and longer length of hospital stay.There was no significant difference in OS and CSS according to surgical approaches(pZ0.653,and 0.816,respectively).Subgroup analysis revealed that OS and CSS were not significantly different regardless of the status of extravesical involvement or LN involvement.Multivariable Cox regression analyses showed that the surgical approach was not a significant predictor of OS and CSS.Conclusions:Our study showed that MIRC was comparable to conventional ORC in terms of OS and CSS.展开更多
The M_(W)7.4 Maduo earthquake occurred on 22 May 2021 at 02:04 CST with a large-expansion surface rupture.This earthquake was located in the Bayan Har block at the eastern Tibetan Plateau,where eight earthquakes of M_...The M_(W)7.4 Maduo earthquake occurred on 22 May 2021 at 02:04 CST with a large-expansion surface rupture.This earthquake was located in the Bayan Har block at the eastern Tibetan Plateau,where eight earthquakes of M_(S)>7.0 have occurred in the past 25 years.Here,we combined interferometric synthetic aperture radar,GPS,and teleseismic data to study the coseismic slip distribution,fault geometry,and dynamic source rupture process of the Maduo earthquake.We found that the overall coseismic deformation field of the Maduo earthquake is distributed in the NWW-SEE direction along 285°.There was slight bending at the western end and two branches at the eastern end.The maximum slip is located near the eastern bending area on the northern branch of the fault system.The rupture nucleated on the Jiangcuo fault and propagated approximately 160 km along-strike in both the NWW and SEE directions.The characteristic source rupture process of the Maduo earthquake is similar to that of the 2010 M_(W)6.8 Yushu earthquake,indicating that similar earthquakes with large-expansion surface ruptures and small shallow slip deficits can occur on both the internal fault and boundary fault of the Bayan Har block.展开更多
The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and ...The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and mechanism of soaked-dried coal's spontaneous combustion.Five samples of coal were dried to various degrees,and the weight loss features during thermal processing were examined.Based on this,the pore structure and chemical structure characteristics of the coal samples with the highest tendency to spontaneous combustion were quantitatively examined,and the mechanism by which soaking-drying afected the spontaneous combustion heating process of the remaining coal in goaf was investigated in turn.The results show that T1 decreases with the increase of drying time,T2–T6 shows a fuctuating change,and the ignition activation energy of 36-S-Coal is smaller than that of other coal samples.The pore type of 36-S-Coal changes from a oneend closed impermeable pore to an open pore,and the pore group area is large.During the 36 h drying process,the internal channels of the coal were dredged,and a large number of gravels and minerals were precipitated from the pores with the air fow.A large number of gravels were around the pores to form a surface structure that was easy to adsorb various gases.Furthermore,infrared spectroscopy was used to analyze the two coal samples.It was found that soaking and drying did not change the functional group types of coal samples,but the fatty chain degree of 36-S-Coal was reduced to 1.56.It shows that the aliphatic chain structure of coal is changed after 36 h of drying after 30 days of soaking,which leads to the continuous shedding of aliphatic chain branches of residual coal,and the skeleton of coal is looser,which makes the low-temperature oxidation reaction of 36-S-Coal easier.Based on the above results,the coal-oxygen composite mechanism of water-immerseddried coal is obtained,and it is considered that the key to the spontaneous combustion oxidation process of coal is to provide oxygen atoms and accelerate the formation of peroxides.展开更多
The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot re...The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot research topic. With Cetyltrimethyl Ammonium Bromide (CTAB) and Diethylamine (DEA) as templates, a two-step crystallization process was employed to synthesize hierarchical SAPO-34 molecular sieves. We found that the aging process is vital for the formation of pure phase SAPO-34. It was investigated the relationship of crystallinity trend and mesoporous content with the crystallization time. The results showed that the prolongation of crystallization time was beneficial to enhance the crystallinity of the molecular sieve, but unfavourable to the retention of mesoporous structure. The formation process of hierarchical SAPO-34 molecular sieve involved agglomeration, disintegration, crystallization, re-agglomeration and growth. The hierarchical SAPO-34 molecular sieve with a satisfactory crystallinity and considerable mesoporous structure could be obtained after 36 hours of crystallization. Moreover, the sample had the most suitable acid strength as well as acid amount. The catalytic activity was investigated by catalytic dimethyl ether (DME) to olefin (DTO) reaction. It revealed that the conversion of DME and the selectivity to olefins over the hierarchical SAPO-34 molecular sieve were significantly enhanced with comparison to that over microporous SAPO-34 molecular sieve. The amount of coke deposition of the hierarchical SAPO-34 molecular sieve (14.2%) was lower than that over the microporous molecular sieve (16.5%). Meanwhile, the propylene selectivity of hierarchical SAPO-34 was higher than that of microporous SAPO-34 in the whole reaction. In a word, the hierarchical SAPO-34 molecular sieve synthesized in this study showed a longer catalytic life, higher coke deposition resistance and higher propylene selectivity.展开更多
First,the hierarchical ZSM-5 zeolite was prepared by hydrothermal method using mesoporous template cetyltrimethylammonium bromide(CTAB).The physical and chemical properties of the hierarchical ZSM-5 zeolite were chara...First,the hierarchical ZSM-5 zeolite was prepared by hydrothermal method using mesoporous template cetyltrimethylammonium bromide(CTAB).The physical and chemical properties of the hierarchical ZSM-5 zeolite were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and N2 adsorption-desorption and Scanning electron microscope(SEM).Then,the as-prepared hierarchical ZSM-5 zeolite and ion exchange resin were used as catalysts to evaluate the reaction performance of the synthesis of tributyl citrate.Compared with the ion exchange resin,the as-prepared ZSM-5 has a microporous and mesoporous composite structure and a large specific surface area,so that significantly improving the catalytic performance of synthesizing tributyl citrate and increasing the esterification rate of the reaction 8.7%.展开更多
We investigated the effects of graphene on the model herb Artemisia annua,which is renowned for produc-ing artemisinin,a widely used pharmacological compound.Seedling growth and biomass were promoted when A.annua was ...We investigated the effects of graphene on the model herb Artemisia annua,which is renowned for produc-ing artemisinin,a widely used pharmacological compound.Seedling growth and biomass were promoted when A.annua was cultivated with low concentrations of graphene,an effect which was attributed to a 1.4-fold increase in nitrogen uptake,a 15%–22%increase in chlorophyllfluorescence,and greater abun-dance of carbon cycling–related bacteria.Exposure to 10 or 20 mg/L graphene resulted in a�60%increase in H2O2,and graphene could act as a catalyst accelerator,leading to a 9-fold increase in catalase(CAT)ac-tivity in vitro and thereby maintaining reactive oxygen species(ROS)homeostasis.Importantly,graphene exposure led to an 80%increase in the density of glandular secreting trichomes(GSTs),in which artemisinin is biosynthesized and stored.This contributed to a 5%increase in artemisinin content inmature leaves.Inter-estingly,expression of miR828 was reduced by both graphene and H2O2 treatments,resulting in induction of its target gene AaMYB17,a positive regulator of GST initiation.Subsequent molecular and genetic assays showed that graphene-induced H2O2 inhibits micro-RNA(miRNA)biogenesis through Dicers and regulates the miR828–AaMYB17 module,thus affecting GST density.Our results suggest that graphene may contribute to yield improvement in A.annua via dynamic physiological processes together with miRNA regulation,and it may thus represent a new cultivation strategy for increasing yield capacity through nanobiotechnology.展开更多
Accurately predicting the chiller coefficient of performance(COP)is essential for improving the energy efficiency of heating,ventilation,and air conditioning(HVAC)systems,significantly contributing to energy conservat...Accurately predicting the chiller coefficient of performance(COP)is essential for improving the energy efficiency of heating,ventilation,and air conditioning(HVAC)systems,significantly contributing to energy conservation in buildings.Traditional performance prediction methods often overlook the dynamic interaction among sensor variables and face challenges in using extensive historical data efficiently,which impedes accurate predictions.To overcome these challenges,this paper proposes an innovative on-site chiller performance prediction method employing a dynamic graph convolutional network(GCN)enhanced by association rules.The distinctive feature of this method is constructing an association graph bank containing static graphs in each operating mode by mining the association rules between various sensor variables in historical operating data.A real-time graph is created by analyzing the correlation between various sensor variables in the current operating data.This graph is fused online with the static graph in the current operating mode to obtain a dynamic graph used for feature extraction and training of GCN.The effectiveness of this method has been empirically confirmed through the operational data of an actual building chiller system.Comparative analysis with state-of-the-art methods highlights the superior performance of the proposed method.展开更多
TiO2/graphene composite photocatalysts have been prepared by a simple liquid phase deposition method using titanium tetrafluoride and electron beam (EB) irradiation-pretreated graphene as the raw materials. The prod...TiO2/graphene composite photocatalysts have been prepared by a simple liquid phase deposition method using titanium tetrafluoride and electron beam (EB) irradiation-pretreated graphene as the raw materials. The products were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The effects of varying the synthesis parameters such as graphene content, concentration of titanium tetrafluoride solution and irradiation dose were investigated. It was found that the preparation conditions had a significant effect on the structure and properties of the final products. The irradiated graphene was covered with petal-like anatase TiO2 nanoparticles, which were more uniform and smaller in size than those in products synthesized without EB irradiation-pretreated graphene. The photocatalytic activities of the products were evaluated using the photocatalytic degradation of methyl orange as a probe reaction. The results showed that the products synthesized using EB irradiation-pretreated graphene exhibited higher photocatalytic activities than those using graphene without EB irradiation pretreatment.展开更多
Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,nu...Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,numerous research on cotton has navigated various aspects,from multi-genome assembly,genome editing,mechanism of fiber development,metabolite biosynthesis,and analysis to genetic breeding.Genomic and 3D genomic studies reveal the origin of cotton species and the spatiotemporal asymmetric chromatin structure in fibers.Mature multiple genome editing systems,such as CRISPR/Cas9,Cas12(Cpf1)and cytidine base editing(CBE),have been widely used in the study of candidate genes affecting fiber development.Based on this,the cotton fiber cell development network has been preliminarily drawn.Among them,the MYB-b HLH-WDR(MBW)transcription factor complex and IAA and BR signaling pathway regulate the initiation;various plant hormones,including ethylene,mediated regulatory network and membrane protein overlap fine-regulate elongation.Multistage transcription factors targeting Ces A 4,7,and 8 specifically dominate the whole process of secondary cell wall thickening.And fluorescently labeled cytoskeletal proteins can observe real-time dynamic changes in fiber development.Furthermore,research on the synthesis of cotton secondary metabolite gossypol,resistance to diseases and insect pests,plant architecture regulation,and seed oil utilization are all conducive to finding more high-quality breeding-related genes and subsequently facilitating the cultivation of better cotton varieties.This review summarizes the paramount research achievements in cotton molecular biology over the last few decades from the above aspects,thereby enabling us to conduct a status review on the current studies of cotton and provide strong theoretical support for the future direction.展开更多
High-entropy alloys(HEAs)have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications.Herein,for the first time,we propose a surface strain strategy ...High-entropy alloys(HEAs)have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications.Herein,for the first time,we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction(MOR).High-resolution aberration-corrected scanning transmission electron microscopy(STEM)and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic(FCC)crystalline structure in Pt Fe Co Ni Cu HEAs.The HEAs obtained by heat treatment at 700℃(HEA-700)exhibit 0.94%compressive strain compared with that obtained at 400℃(HEA-400).As expected,the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art catalysts.The enhanced MOR activity can be attributed to a shorter Pt–Pt bond distance in HEA-700 resulting from compressive strain.The nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt layer.This work presents a new perspective for the design of high-performance HEAs electrocatalysts.展开更多
Tailoring the nanostructure/morphology and chemical composition is important to regulate the electronic configuration of electrocatalysts and thus enhance their performance for water and urea electrolysis.Herein,the n...Tailoring the nanostructure/morphology and chemical composition is important to regulate the electronic configuration of electrocatalysts and thus enhance their performance for water and urea electrolysis.Herein,the nitrogen-doped carbon-decorated tricomponent metal phosphides of FeP4 nanotube@Ni-Co-P nanocage(NC-FNCP)with unique nested hollow architectures are fabricated by a self-sacrifice template strategy.Benefiting from the multi-component synergy,the modification of nitrogen-doped carbon,and the modulation of nested porous hollow morphology,NC-FNCP facilitates rapid electron/mass transport in water and urea electrolysis.NC-FNCP-based anode shows low potentials of 248 mV and 1.37 V(vs.reversible hydrogen electrode)to attain 10 mA/cm^(2) for oxygen evolution reaction(OER)and urea oxidation reaction(UOR),respectively.In addition,the overall urea electrolysis drives 10 mA/cm^(2) at a comparatively low voltage of 1.52 V(vs.RHE)that is 110 mV lower than that of overall water electrolysis,as well as exhibits excellent stability over 20 h.This work strategizes a multi-shell-structured electrocatalyst with multi-compositions and explores its applications in a sustainable combination of hydrogen production and sewage remediation.展开更多
Efficient ethanol oxidation reaction(EOR)is challenging due to the multiple reaction steps required to accomplish full oxidation to CO_(2) in fuel cells.Highentropy materials with the adjustable composition and unique...Efficient ethanol oxidation reaction(EOR)is challenging due to the multiple reaction steps required to accomplish full oxidation to CO_(2) in fuel cells.Highentropy materials with the adjustable composition and unique chemical structure provide a large configurational space for designing high-performance electrocatalysts.Herein,a new class of structurally ordered PtRhFeNiCu high-entropy intermetallics(HEIs)is developed as electrocatalyst,which exhibits excellent electrocatalytic activity and CO tolerance for EOR compared to high-entropy alloys(HEAs)comprising of same elements.When the HEIs are used as anode catalysts to be assembled into a high-temperature polybenzimidazole-based direct ethanol fuel cell,the HEIs achieve a high power density of 47.50 mW/cm^(2),which is 2.97 times of Pt/C(16.0mW/cm^(2)).Online gas chromatography measurements show that the developed HEIs have a stronger C–C bond-breaking ability than corresponding HEAs and Pt/C catalysts,which is further verified by density functional theory(DFT)calculations.Moreover,DFT results indicate that HEIs possess higher stability and electrochemical activity for EOR than HEAs.These results demonstrate that the HEIs could provide a new platform to develop highperformance electrocatalysts for broader applications.展开更多
The tactile pressure sensor is of great significance in flexible electronics,but sensitivity customization over the required working range with high linearity still remains a critical challenge.Despite numerous effort...The tactile pressure sensor is of great significance in flexible electronics,but sensitivity customization over the required working range with high linearity still remains a critical challenge.Despite numerous efforts to achieve high sensitivity and a wide working range,most sensitive microstructures tend to be obtained only by inverting naturally existing templates without rational design based on fundamental contact principles or models for piezoresistive pressure sensors.Here,a positive design strategy with a hyperelastic model and a Hertzian contact model for comparison was proposed to develop a flexible pressure sensor with highly customizable linear sensitivity and linearity,in which the microstructure distribution was precalculated according to the desired requirement prior to fabrication.As a proof of concept,three flexible pressure sensors exhibited sensitivities of 0.7,1.0,and 1.3 kPa−1 over a linear region of up to 200 kPa,with a low sensitivity error(<5%)and high linearity(~0.99),as expected.Based on the superior electromechanical performance of these sensors,potential applications in physiological signal recognition are demonstrated as well,and such a strategy could shed more light on demand-oriented scenarios,including designable working ranges and linear sensitivity for next-generation wearable devices.展开更多
Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a seri...Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a series of phosphorus-doped Fe_(7)S_(8)nanowires integrated within carbon(P-Fe_(7)S_(8)@C)are rationally synthesized via a one-step phosphorization of one-dimensional(1D)Fe-based organicinorganic nanowires.The as-obtained P-Fe_(7)S_(8)@C catalysts with modified electronic configurations present typical porous structure,providing plentiful active sites for rapid reaction kinetics.Density functional calculations demonstrate that the doping Fe_(7)S_(8)with P can effectively enhance the electron density of Fe_(7)S_(8)around the Fermi level and weaken the Fe-H bonding,leading to the decrease of adsorption free energy barrier on active sites.As a result,the optimal catalyst of P-Fe_(7)S_(8)-600@C exhibits a relatively low overpotential of 136 mV for hydrogen evolution reaction(HER)to reach the current density of 10 mA/cm^(2),and a significantly low overpotential of 210 mV for oxygen evolution reaction(OER)at 20 mA/cm^(2)in alkaline media.The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.展开更多
This paper addresses the predefined-time bipartite tracking problem for second-order Multi-Agent Systems(MASs)with undirected signed topologies.A group of observers,which can estimate the state tracking errors for eac...This paper addresses the predefined-time bipartite tracking problem for second-order Multi-Agent Systems(MASs)with undirected signed topologies.A group of observers,which can estimate the state tracking errors for each follower in a pre-specified time,is proposed based on the time-varying function.In order to deal with the uncertainties caused by the unknown disturbances and the unknown input signal of the leader,we propose a predefined-time distributed control protocol based on the sliding mode control method.In addition,an auxiliary dynamic sliding variable is designed to reduce system chattering.Wetheoretically prove that the two control protocols can drive the state trajectories of each follower to reach the corresponding sliding surface within a specified time,and finally ensure that the prescribed-time bipartite tracking consensus is achieved for the MASs.Simulations are provided to verify the proposed schemes,and the simulation results further confirm the superiority of the adaptive control protocol.展开更多
基金supported in part by the National Major Scientific Research Equipment of China (61927803)the National Natural Science Foundation of China Basic Science Center Project (61988101)+1 种基金Science and Technology Innovation Program of Hunan Province (2021RC4054)the China Postdoctoral Science Foundation (2021M691681)。
文摘The copper disc casting machine is core equipment for producing copper anode plates in the copper metallurgy industry.The copper disc casting machine casting package motion curve(CPMC) is significant for precise casting and efficient production.However,the lack of exact casting modeling and real-time simulation information severely restricts dynamic CPMC optimization.To this end,a liquid copper droplet model describes the casting package copper flow pattern in the casting process.Furthermore,a CPMC optimization model is proposed for the first time.On top of this,a digital twin dual closed-loop self-optimization application framework(DT-DCS) is constructed for optimizing the copper disc casting process to achieve self-optimization of the CPMC and closed-loop feedback of manufacturing information during the casting process.Finally,a case study is carried out based on the proposed methods in the industrial field.
文摘Objective:To investigate current status of diagnosis and treatment of bladder cancer in China.Methods:A database was generated by Chinese Bladder Cancer Consortium(CBCC).From January 2007 to December 2012,14,260 cases from 44 CBCC centers were included.Data of diagnosis,treatment and pathology were collected.Results:The average age was 63.5 year-old and most patients were male(84.3%).The most common histologic types were urothelial carcinoma(91.4%),adenocarcinoma(1.8%),and squamous carcinoma(1.9%).According to 1973 and 2004 WHO grading system,42.0%,41.0%,and 17.0% of patients were grade 1,2,and 3,and 16.0%,48.7%,and 35.3% of patients were papillary urothelial neoplasms of low malignant potential,low,and high grade,respectively.Non-muscle invasive bladder cancer(NMIBC)and muscle invasive bladder cancer(MIBC)were 25.2% and 74.1%,respectively(0.8% not clear).Carcinoma in situ was only 2.4%.Most patients were diagnosed by white-light cystoscopy with biopsy(74.3%).Fluorescence and narrow band imaging cystoscopy had additional detection rate of 1.0% and 4.0%,respectively.Diagnostic transurethral resection(TUR)provided detection rate of 16.9%.Most NMIBCs were treated with TUR(89.2%).After initial TUR,2.6%accepted second TUR,and 45.7%,69.9%,and 58.7% accepted immediate,induced,and maintenance chemotherapy instillation,respectively.Most MIBCs were treated with radical cystectomy(RC,59.7%).Laparoscopic RCs were 35.1%,while open RC 63.4%.Extended and standard pelvic lymph node dissection were 7% and 66%,respectively.Three most common urinary diversions were orthotopic neobladder(44%),ileal conduit(31%),and ureterocutaneostomy(23%).Only 2.3% of patients accepted neo-adjuvant chemotherapy and only 18%of T3 and T4 patients accepted adjuvant chemotherapy.Conclusion:Disease characteristics are similar to international reports,while differences of diagnosis and treatment exist.This study can provide evidences for revisions of the guideline on bladder cancer in China.
基金Erwin Edward Hart Professorship, Natural Sciences and Engineering Research Council of Canada (NSERC, RGPIN-2018-04642)University of Toronto for financial supports, and China Scholarship Council under Grant No. 201906270124。
文摘Hydrogen has been identified as one of the most promising sustainable and clean energy. Developing hydrogen evolution reaction(HER) catalyst with high activity is essential for satisfying the future requirements. Considering novel advantages of two-dimensional materials and high catalytic activity of atomic transition metal, in this study, using density functional theory calculation, the HER on single transitionmetal(23 different TM atoms) doped phosphorus carbide monolayer(α-PC) has been investigated. The Volmer–Tafel and Volmer–Heyrovsky reaction mechanisms, and the stability of the most promising HER catalyst are also included. The results show that Ir-αPC with high physical and thermal stability has the most optimal value of Gibbs free adsorption energy for H atom. The relationship of d band center and the HER activity shows a volcano-like curve. The calculation of reaction energy barrier indicates that the Volmer-Heyrovsky step is more favorable than the Volmer-Tafel step.
基金supported by the National Natural Science Foundation of China(Grant No.81825016,81772719,81772728,81572514)the Key Areas Research and Development Program of Guangdong(Grant No.2018B010109006)Medical Scientific Research Foundation of Guangdong Province(Grant No.A2018388).
文摘Objective:To investigate oncological outcomes in patients with bladder cancer who underwent minimally invasive radical cystectomy(MIRC)or open radical cystectomy(ORC).Methods:We identified patients with bladder cancer who underwent radical cystectomy(RC)in 13 centers of the Chinese Bladder Cancer Consortium(CBCC).Perioperative outcomes were compared between MIRC and ORC.The influence of surgical approaches on overall survival(OS)and cancer-specific survival(CSS)in the entire study group and subgroups classified according to pathologic stage or lymph node(LN)status was assessed with the log-rank test.Multivariable Cox proportional hazard models were used to evaluate the association among OS,CSS and risk factors of interest.Results:Of 2098 patients who underwent RC,1243 patients underwent MIRC(1087 laparoscopic RC and 156 robotic-assisted RC,respectively),while 855 patients underwent ORC.No significant differences were noted in positive surgical margin rate and 90-day postoperative mortality rate.MIRC was associated with less estimated blood loss,more LN yield,higher rate of neobladder diversion,longer operative time,and longer length of hospital stay.There was no significant difference in OS and CSS according to surgical approaches(pZ0.653,and 0.816,respectively).Subgroup analysis revealed that OS and CSS were not significantly different regardless of the status of extravesical involvement or LN involvement.Multivariable Cox regression analyses showed that the surgical approach was not a significant predictor of OS and CSS.Conclusions:Our study showed that MIRC was comparable to conventional ORC in terms of OS and CSS.
基金supported by grants of the K.C.Wong Education Foundation(No.GJTD-2019-04)Second Tibetan Plateau Scientific Expedition and Research Program(No.2019QZKK07)National Nature Science Foundation of China(No.41988101-0104)。
文摘The M_(W)7.4 Maduo earthquake occurred on 22 May 2021 at 02:04 CST with a large-expansion surface rupture.This earthquake was located in the Bayan Har block at the eastern Tibetan Plateau,where eight earthquakes of M_(S)>7.0 have occurred in the past 25 years.Here,we combined interferometric synthetic aperture radar,GPS,and teleseismic data to study the coseismic slip distribution,fault geometry,and dynamic source rupture process of the Maduo earthquake.We found that the overall coseismic deformation field of the Maduo earthquake is distributed in the NWW-SEE direction along 285°.There was slight bending at the western end and two branches at the eastern end.The maximum slip is located near the eastern bending area on the northern branch of the fault system.The rupture nucleated on the Jiangcuo fault and propagated approximately 160 km along-strike in both the NWW and SEE directions.The characteristic source rupture process of the Maduo earthquake is similar to that of the 2010 M_(W)6.8 Yushu earthquake,indicating that similar earthquakes with large-expansion surface ruptures and small shallow slip deficits can occur on both the internal fault and boundary fault of the Bayan Har block.
基金supported by the fnancial support of the General Projects of National Natural Science Foundation of China(52074156).
文摘The physical and chemical properties of the air-dried residual coal after soaking in the goaf will change,resulting in an increase in its spontaneous combustion tendency.This study aimed to look into the features and mechanism of soaked-dried coal's spontaneous combustion.Five samples of coal were dried to various degrees,and the weight loss features during thermal processing were examined.Based on this,the pore structure and chemical structure characteristics of the coal samples with the highest tendency to spontaneous combustion were quantitatively examined,and the mechanism by which soaking-drying afected the spontaneous combustion heating process of the remaining coal in goaf was investigated in turn.The results show that T1 decreases with the increase of drying time,T2–T6 shows a fuctuating change,and the ignition activation energy of 36-S-Coal is smaller than that of other coal samples.The pore type of 36-S-Coal changes from a oneend closed impermeable pore to an open pore,and the pore group area is large.During the 36 h drying process,the internal channels of the coal were dredged,and a large number of gravels and minerals were precipitated from the pores with the air fow.A large number of gravels were around the pores to form a surface structure that was easy to adsorb various gases.Furthermore,infrared spectroscopy was used to analyze the two coal samples.It was found that soaking and drying did not change the functional group types of coal samples,but the fatty chain degree of 36-S-Coal was reduced to 1.56.It shows that the aliphatic chain structure of coal is changed after 36 h of drying after 30 days of soaking,which leads to the continuous shedding of aliphatic chain branches of residual coal,and the skeleton of coal is looser,which makes the low-temperature oxidation reaction of 36-S-Coal easier.Based on the above results,the coal-oxygen composite mechanism of water-immerseddried coal is obtained,and it is considered that the key to the spontaneous combustion oxidation process of coal is to provide oxygen atoms and accelerate the formation of peroxides.
文摘The hierarchical structure can significantly improve the diffusion efficiency of the catalyst and regulate the product distribution. Therefore, the preparation of hierarchical SAPO-34 molecular sieve has been a hot research topic. With Cetyltrimethyl Ammonium Bromide (CTAB) and Diethylamine (DEA) as templates, a two-step crystallization process was employed to synthesize hierarchical SAPO-34 molecular sieves. We found that the aging process is vital for the formation of pure phase SAPO-34. It was investigated the relationship of crystallinity trend and mesoporous content with the crystallization time. The results showed that the prolongation of crystallization time was beneficial to enhance the crystallinity of the molecular sieve, but unfavourable to the retention of mesoporous structure. The formation process of hierarchical SAPO-34 molecular sieve involved agglomeration, disintegration, crystallization, re-agglomeration and growth. The hierarchical SAPO-34 molecular sieve with a satisfactory crystallinity and considerable mesoporous structure could be obtained after 36 hours of crystallization. Moreover, the sample had the most suitable acid strength as well as acid amount. The catalytic activity was investigated by catalytic dimethyl ether (DME) to olefin (DTO) reaction. It revealed that the conversion of DME and the selectivity to olefins over the hierarchical SAPO-34 molecular sieve were significantly enhanced with comparison to that over microporous SAPO-34 molecular sieve. The amount of coke deposition of the hierarchical SAPO-34 molecular sieve (14.2%) was lower than that over the microporous molecular sieve (16.5%). Meanwhile, the propylene selectivity of hierarchical SAPO-34 was higher than that of microporous SAPO-34 in the whole reaction. In a word, the hierarchical SAPO-34 molecular sieve synthesized in this study showed a longer catalytic life, higher coke deposition resistance and higher propylene selectivity.
文摘First,the hierarchical ZSM-5 zeolite was prepared by hydrothermal method using mesoporous template cetyltrimethylammonium bromide(CTAB).The physical and chemical properties of the hierarchical ZSM-5 zeolite were characterized by X-ray diffraction(XRD),Fourier transform infrared spectroscopy(FT-IR)and N2 adsorption-desorption and Scanning electron microscope(SEM).Then,the as-prepared hierarchical ZSM-5 zeolite and ion exchange resin were used as catalysts to evaluate the reaction performance of the synthesis of tributyl citrate.Compared with the ion exchange resin,the as-prepared ZSM-5 has a microporous and mesoporous composite structure and a large specific surface area,so that significantly improving the catalytic performance of synthesizing tributyl citrate and increasing the esterification rate of the reaction 8.7%.
基金supported by the National Natural Science Foundation of China (82274047 and 52071192)the National Key R&D Program of China (2018YFA0900600)+3 种基金the Engineering Research Center of Coal-Based Ecological Carbon Sequestration Technology of the Ministry of Education (MJST2023-3)the China Postdoctoral Science Foundation (2023M732232)SJTU Trans-med Awards Research (20190104)supported in part by the Bill&Melinda Gates Foundation (OPP1199872 and INV-027291).
文摘We investigated the effects of graphene on the model herb Artemisia annua,which is renowned for produc-ing artemisinin,a widely used pharmacological compound.Seedling growth and biomass were promoted when A.annua was cultivated with low concentrations of graphene,an effect which was attributed to a 1.4-fold increase in nitrogen uptake,a 15%–22%increase in chlorophyllfluorescence,and greater abun-dance of carbon cycling–related bacteria.Exposure to 10 or 20 mg/L graphene resulted in a�60%increase in H2O2,and graphene could act as a catalyst accelerator,leading to a 9-fold increase in catalase(CAT)ac-tivity in vitro and thereby maintaining reactive oxygen species(ROS)homeostasis.Importantly,graphene exposure led to an 80%increase in the density of glandular secreting trichomes(GSTs),in which artemisinin is biosynthesized and stored.This contributed to a 5%increase in artemisinin content inmature leaves.Inter-estingly,expression of miR828 was reduced by both graphene and H2O2 treatments,resulting in induction of its target gene AaMYB17,a positive regulator of GST initiation.Subsequent molecular and genetic assays showed that graphene-induced H2O2 inhibits micro-RNA(miRNA)biogenesis through Dicers and regulates the miR828–AaMYB17 module,thus affecting GST density.Our results suggest that graphene may contribute to yield improvement in A.annua via dynamic physiological processes together with miRNA regulation,and it may thus represent a new cultivation strategy for increasing yield capacity through nanobiotechnology.
基金supported in part by the Science and Technology Innovation Program of Hunan Province(No.2022RC1090)in part by the National Natural Science Foundation of China(No.62173349)+2 种基金in part by the Natural Science Foundation of Hunan Province(No.2022J20076)in part by the Innovation Driven Projection of Central South University(No.2023CXQD073)in part by the Major Program of Xiangjiang Laboratory(No.22XJ01005).
文摘Accurately predicting the chiller coefficient of performance(COP)is essential for improving the energy efficiency of heating,ventilation,and air conditioning(HVAC)systems,significantly contributing to energy conservation in buildings.Traditional performance prediction methods often overlook the dynamic interaction among sensor variables and face challenges in using extensive historical data efficiently,which impedes accurate predictions.To overcome these challenges,this paper proposes an innovative on-site chiller performance prediction method employing a dynamic graph convolutional network(GCN)enhanced by association rules.The distinctive feature of this method is constructing an association graph bank containing static graphs in each operating mode by mining the association rules between various sensor variables in historical operating data.A real-time graph is created by analyzing the correlation between various sensor variables in the current operating data.This graph is fused online with the static graph in the current operating mode to obtain a dynamic graph used for feature extraction and training of GCN.The effectiveness of this method has been empirically confirmed through the operational data of an actual building chiller system.Comparative analysis with state-of-the-art methods highlights the superior performance of the proposed method.
基金The work was co-supported by the National Natural Science Foundation of China (No. 20871081), the Science and Technology Commission of Shanghai Municipality (Nos. 10QH1401000 and 10DZ0500100), the Research Funding of the State Key Laboratory of Chemical Engineering (ECUST), the Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry (ECNU), and Shanghai Leading Academic Disciplines (No. $30109).
文摘TiO2/graphene composite photocatalysts have been prepared by a simple liquid phase deposition method using titanium tetrafluoride and electron beam (EB) irradiation-pretreated graphene as the raw materials. The products were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The effects of varying the synthesis parameters such as graphene content, concentration of titanium tetrafluoride solution and irradiation dose were investigated. It was found that the preparation conditions had a significant effect on the structure and properties of the final products. The irradiated graphene was covered with petal-like anatase TiO2 nanoparticles, which were more uniform and smaller in size than those in products synthesized without EB irradiation-pretreated graphene. The photocatalytic activities of the products were evaluated using the photocatalytic degradation of methyl orange as a probe reaction. The results showed that the products synthesized using EB irradiation-pretreated graphene exhibited higher photocatalytic activities than those using graphene without EB irradiation pretreatment.
基金the National Natural Science Foundation of China(32200286)the China Postdoctoral Science Foundation(2022TQ0240,2022M722470)。
文摘Cotton is an irreplaceable economic crop currently domesticated in the human world for its extremely elongated fiber cells specialized in seed epidermis,which makes it of high research and application value.To date,numerous research on cotton has navigated various aspects,from multi-genome assembly,genome editing,mechanism of fiber development,metabolite biosynthesis,and analysis to genetic breeding.Genomic and 3D genomic studies reveal the origin of cotton species and the spatiotemporal asymmetric chromatin structure in fibers.Mature multiple genome editing systems,such as CRISPR/Cas9,Cas12(Cpf1)and cytidine base editing(CBE),have been widely used in the study of candidate genes affecting fiber development.Based on this,the cotton fiber cell development network has been preliminarily drawn.Among them,the MYB-b HLH-WDR(MBW)transcription factor complex and IAA and BR signaling pathway regulate the initiation;various plant hormones,including ethylene,mediated regulatory network and membrane protein overlap fine-regulate elongation.Multistage transcription factors targeting Ces A 4,7,and 8 specifically dominate the whole process of secondary cell wall thickening.And fluorescently labeled cytoskeletal proteins can observe real-time dynamic changes in fiber development.Furthermore,research on the synthesis of cotton secondary metabolite gossypol,resistance to diseases and insect pests,plant architecture regulation,and seed oil utilization are all conducive to finding more high-quality breeding-related genes and subsequently facilitating the cultivation of better cotton varieties.This review summarizes the paramount research achievements in cotton molecular biology over the last few decades from the above aspects,thereby enabling us to conduct a status review on the current studies of cotton and provide strong theoretical support for the future direction.
基金supported by the National Natural Science Foundation of China (51402100, 21573066, 21825201, 22002039, and 21522305)the Scientific Research Foundation of Hunan Provincial Education Department (19C0054)+2 种基金the Postgraduate Scientific Research Innovation Project of Hunan Province (CX20200441)the Australian Research Council (CE 140100012)the Australian National Fabrication Facility | UOW Electron Microscopy Centre, and Compute Canada, Natural Sciences and Engineering Research Council of Canada (NSERC), University of Toronto
文摘High-entropy alloys(HEAs)have been widely studied due to their unconventional compositions and unique physicochemical properties for various applications.Herein,for the first time,we propose a surface strain strategy to tune the electrocatalytic activity of HEAs for methanol oxidation reaction(MOR).High-resolution aberration-corrected scanning transmission electron microscopy(STEM)and elemental mapping demonstrate both uniform atomic dispersion and the formation of a face-centered cubic(FCC)crystalline structure in Pt Fe Co Ni Cu HEAs.The HEAs obtained by heat treatment at 700℃(HEA-700)exhibit 0.94%compressive strain compared with that obtained at 400℃(HEA-400).As expected,the specific activity and mass activity of HEA-700 is higher than that of HEA-400 and most of the state-of-the-art catalysts.The enhanced MOR activity can be attributed to a shorter Pt–Pt bond distance in HEA-700 resulting from compressive strain.The nonprecious metal atoms in the core could generate compressive strain and down shift d-band centers via electron transfer to surface Pt layer.This work presents a new perspective for the design of high-performance HEAs electrocatalysts.
基金the National Natural Science Foundation of China(No.21601120)the Science and Technology Commission of Shanghai Municipality(Nos.17ZR1410500 and 19ZR1418100)+3 种基金Science and Technology Program of Shanghai(No.21010500300)STINT Joint China-Sweden Mobility Project(No.CH2017-7243)Swedish Government strategic faculty grant in material science(SFO,MATLIU)in Advanced Functional Materials(AFM)(VR Dnr.5.1-2015-5959)We also appreciate the High-Performance Computing Center of Shanghai University,and Shanghai Engineering Research Center of Intelligent Computing System(No.19DZ2252600)for providing the computing resources and technical support.
文摘Tailoring the nanostructure/morphology and chemical composition is important to regulate the electronic configuration of electrocatalysts and thus enhance their performance for water and urea electrolysis.Herein,the nitrogen-doped carbon-decorated tricomponent metal phosphides of FeP4 nanotube@Ni-Co-P nanocage(NC-FNCP)with unique nested hollow architectures are fabricated by a self-sacrifice template strategy.Benefiting from the multi-component synergy,the modification of nitrogen-doped carbon,and the modulation of nested porous hollow morphology,NC-FNCP facilitates rapid electron/mass transport in water and urea electrolysis.NC-FNCP-based anode shows low potentials of 248 mV and 1.37 V(vs.reversible hydrogen electrode)to attain 10 mA/cm^(2) for oxygen evolution reaction(OER)and urea oxidation reaction(UOR),respectively.In addition,the overall urea electrolysis drives 10 mA/cm^(2) at a comparatively low voltage of 1.52 V(vs.RHE)that is 110 mV lower than that of overall water electrolysis,as well as exhibits excellent stability over 20 h.This work strategizes a multi-shell-structured electrocatalyst with multi-compositions and explores its applications in a sustainable combination of hydrogen production and sewage remediation.
基金National Key R&D Program of China,Grant/Award Number:2020YFA0710000the National Natural Science Foundation of China,Grant/Award Numbers:21825201,U19A2017 and,22102053+4 种基金the Provincial Natural Science Foundation of Hunan,Grant/Award Numbers:2016TP1009 and,2020JJ5045the Postgraduate Scientific Research Innovation Project of Hunan Province,Grant/Award Number:CX20200441the Australian Research Council,Grant/Award Number:CE 140100012the Australian National Fabrication Facility-UOW Electron Microscopy Centre,Compute Canada,Natural Sciences and Engineering Research Council of Canada(NSERC)the University of Toronto.
文摘Efficient ethanol oxidation reaction(EOR)is challenging due to the multiple reaction steps required to accomplish full oxidation to CO_(2) in fuel cells.Highentropy materials with the adjustable composition and unique chemical structure provide a large configurational space for designing high-performance electrocatalysts.Herein,a new class of structurally ordered PtRhFeNiCu high-entropy intermetallics(HEIs)is developed as electrocatalyst,which exhibits excellent electrocatalytic activity and CO tolerance for EOR compared to high-entropy alloys(HEAs)comprising of same elements.When the HEIs are used as anode catalysts to be assembled into a high-temperature polybenzimidazole-based direct ethanol fuel cell,the HEIs achieve a high power density of 47.50 mW/cm^(2),which is 2.97 times of Pt/C(16.0mW/cm^(2)).Online gas chromatography measurements show that the developed HEIs have a stronger C–C bond-breaking ability than corresponding HEAs and Pt/C catalysts,which is further verified by density functional theory(DFT)calculations.Moreover,DFT results indicate that HEIs possess higher stability and electrochemical activity for EOR than HEAs.These results demonstrate that the HEIs could provide a new platform to develop highperformance electrocatalysts for broader applications.
基金supported by the National Natural Science Foundation of China (52075464)the National Key Research and Development Program of China (2021YFB3203302)+1 种基金the Special Funds from the Central Government to Guide Local Scientific and Technological Development (2021Szvup068)the Beijing Key Laboratory of Long-life Technology of Precise Rotation and Transmission Mechanisms (BZ0388202106).
文摘The tactile pressure sensor is of great significance in flexible electronics,but sensitivity customization over the required working range with high linearity still remains a critical challenge.Despite numerous efforts to achieve high sensitivity and a wide working range,most sensitive microstructures tend to be obtained only by inverting naturally existing templates without rational design based on fundamental contact principles or models for piezoresistive pressure sensors.Here,a positive design strategy with a hyperelastic model and a Hertzian contact model for comparison was proposed to develop a flexible pressure sensor with highly customizable linear sensitivity and linearity,in which the microstructure distribution was precalculated according to the desired requirement prior to fabrication.As a proof of concept,three flexible pressure sensors exhibited sensitivities of 0.7,1.0,and 1.3 kPa−1 over a linear region of up to 200 kPa,with a low sensitivity error(<5%)and high linearity(~0.99),as expected.Based on the superior electromechanical performance of these sensors,potential applications in physiological signal recognition are demonstrated as well,and such a strategy could shed more light on demand-oriented scenarios,including designable working ranges and linear sensitivity for next-generation wearable devices.
基金the National Natural Science Foundation of China(Nos.21601120 and 21805181)the Science and Technology Commission of Shanghai Municipality(Nos.17ZR1410500 and 19ZR1418100)+1 种基金the High Performance Computing Center of Shanghai UniversityShanghai Engineering Research Center of Intelligent Computing System(No.19DZ2252600)for providing the computing resources and technical support。
文摘Developing low-cost,efficient,and stable non-precious-metal electrocatalysts with controlled crystal structure,morphology and compositions are highly desirable for hydrogen and oxygen evolution reactions.Herein,a series of phosphorus-doped Fe_(7)S_(8)nanowires integrated within carbon(P-Fe_(7)S_(8)@C)are rationally synthesized via a one-step phosphorization of one-dimensional(1D)Fe-based organicinorganic nanowires.The as-obtained P-Fe_(7)S_(8)@C catalysts with modified electronic configurations present typical porous structure,providing plentiful active sites for rapid reaction kinetics.Density functional calculations demonstrate that the doping Fe_(7)S_(8)with P can effectively enhance the electron density of Fe_(7)S_(8)around the Fermi level and weaken the Fe-H bonding,leading to the decrease of adsorption free energy barrier on active sites.As a result,the optimal catalyst of P-Fe_(7)S_(8)-600@C exhibits a relatively low overpotential of 136 mV for hydrogen evolution reaction(HER)to reach the current density of 10 mA/cm^(2),and a significantly low overpotential of 210 mV for oxygen evolution reaction(OER)at 20 mA/cm^(2)in alkaline media.The work presented here may pave the way to design and synthesis of other prominent Fe-based catalysts for water splitting via electronic regulation.
基金the National Natural Science Foundation of China[grant number 61705127].
文摘This paper addresses the predefined-time bipartite tracking problem for second-order Multi-Agent Systems(MASs)with undirected signed topologies.A group of observers,which can estimate the state tracking errors for each follower in a pre-specified time,is proposed based on the time-varying function.In order to deal with the uncertainties caused by the unknown disturbances and the unknown input signal of the leader,we propose a predefined-time distributed control protocol based on the sliding mode control method.In addition,an auxiliary dynamic sliding variable is designed to reduce system chattering.Wetheoretically prove that the two control protocols can drive the state trajectories of each follower to reach the corresponding sliding surface within a specified time,and finally ensure that the prescribed-time bipartite tracking consensus is achieved for the MASs.Simulations are provided to verify the proposed schemes,and the simulation results further confirm the superiority of the adaptive control protocol.