The stability of underground tunnel roofs is strongly influenced by wedge blocks formed by complex joint networks.The mechanical behavior and failure mechanisms of different roof wedge blocks in arched holes were inve...The stability of underground tunnel roofs is strongly influenced by wedge blocks formed by complex joint networks.The mechanical behavior and failure mechanisms of different roof wedge blocks in arched holes were investigated under biaxial stress conditions.The crack evolution and failure modes of the specimens were analyzed through acoustic emission(AE),digital image correlation(DIC),and discrete element method(DEM).Results show significant variations in mechanical properties:specimens T1(extremely unstable triangular)and T2(extremely unstable quadrilateral)exhibited higher strength than T3(extremely stable triangular)and T4(extremely stable quadrilateral),while support more effectively enhanced the strength of T3 and T4.Failure modes were classified as rock-dominated,wedgedominated,or co-dominated.Cracks typically initiated near the wedge and propagated outward.Unsupported specimens developed tensile cracks at the hole bottom,shear cracks at the sides,and mixed cracks along wedge boundaries,whereas supported specimens mainly exhibited cracks at the roof and sides.Stress analysis indicated that unsupported conditions induced high stress differences,promoting localized shear failure.Wedge geometry significantly affected shear stress redistribution at the roof.These findings highlight the critical role of support and wedge block geometry in controlling stress dis-tribution and failure mechanisms in arched tunnels.展开更多
The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions(Mg^(2+))and their strong electrostatic interaction with the primary mate...The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions(Mg^(2+))and their strong electrostatic interaction with the primary material.Consequently,this study successfully developed a MnS/MnO heterostructure through a straightforward hydrothermal and annealing method,marking its initial application in aqueous magnesium ion capacitors(AMICs).The fabricated MnS/MnO heterostructure,characterized by S defects,also generates Mn defects via in-situ initiation of early electrochemical processes.This unique dual ion defects MnS/MnO heterostructure(DID-MnS/MnO)enables the transformation of MnS and MnO,initially not highly active electrochemically for Mg^(2+),into cathode materials exhibiting high electrochemical activity and superior performance.Moreover,DID-MnS/MnO enhances conductivity,improves the kinetics of surface redox reactions,and increases the diffusion rate of Mg^(2+).Furthermore,this study introduces a dual energy storage mechanism for DID-MnS/MnO,which,in conjunction with dual ion defects,offers additional active sites for Mg^(2+)insertion/deinsertion in the host material,mitigating volume expansion and structural degradation during repeated charge-discharge cycles,thereby significantly enhancing cycling reversibility.As anticipated,using a three-electrode system,the developed DID-MnS/MnO demonstrated a discharge specific capacity of 237.9 mAh/g at a current density of 0.1 A/g.Remarkably,the constructed AMIC maintained a capacity retention rate of 94.3%after 10000 cycles at a current density of 1.0 A/g,with a specific capacitance of 165.7 F/g.Hence,DID-MnS/MnO offers insightful perspectives for designing alternative clean energy sources and is expected to contribute significantly to the advancement of the clean energy sector.展开更多
Artificial photosynthesis is an ideal method for solar-to-chemical energy conversion,wherein solar energy is stored in the form of chemical bonds of solar fuels.In particular,the photocatalytic reduction of CO_(2)has ...Artificial photosynthesis is an ideal method for solar-to-chemical energy conversion,wherein solar energy is stored in the form of chemical bonds of solar fuels.In particular,the photocatalytic reduction of CO_(2)has attracted considerable attention due to its dual benefits of fossil fuel production and CO_(2)pollution reduction.However,CO_(2)is a comparatively stable molecule and its photoreduction is thermodynamically and kinetically challenging.Thus,the photocatalytic efficiency of CO_(2)reduction is far below the level of industrial applications.Therefore,development of low-cost cocatalysts is crucial for significantly decreasing the activation energy of CO_(2)to achieving efficient photocatalytic CO_(2)reduction.Herein,we have reported the use of a Ni_(2)P material that can serve as a robust cocatalyst by cooperating with a photosensitizer for the photoconversion of CO_(2).An effective strategy for engineering Ni_(2)P in an ultrathin layered structure has been proposed to improve the CO_(2)adsorption capability and decrease the CO_(2)activation energy,resulting in efficient CO_(2)reduction.A series of physicochemical characterizations including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),and atomic force microscopy(AFM)were used to demonstrate the successful preparation of ultrathin Ni_(2)P nanosheets.The XRD and XPS results confirm the successful synthesis of Ni_(2)P from Ni(OH)2 by a low temperature phosphidation process.According to the TEM images,the prepared Ni_(2)P nanosheets exhibit a 2D and near-transparent sheet-like structure,suggesting their ultrathin thickness.The AFM images further demonstrated this result and also showed that the height of the Ni_(2)P nanosheets is ca 1.5 nm.The photoluminescence(PL)spectroscopy results revealed that the Ni_(2)P material could efficiently promote the separation of the photogenerated electrons and holes in[Ru(bpy)3]Cl2?6H2O.More importantly,the Ni_(2)P nanosheets could more efficiently promote the charge transfer and charge separation rate of[Ru(bpy)3]Cl2?6H2O compared with the Ni_(2)P particles.In addition,the electrochemical experiments revealed that the Ni_(2)P nanosheets,with their high active surface area and charge conductivity,can provide more active centers for CO_(2)conversion and accelerate the interfacial reaction dynamics.These results strongly suggest that the Ni_(2)P nanosheets are a promising material for photocatalytic CO_(2)reduction,and can achieve a CO generation rate of 64.8μmol·h^(-1),which is 4.4 times higher than that of the Ni_(2)P particles.In addition,the XRD and XPS measurements of the used Ni_(2)P nanosheets after the six cycles of the photocatalytic CO_(2)reduction reaction demonstrated their high stability.Overall,this study offers a new function for the 2D transition-metal phosphide catalysts in photocatalytic CO_(2)reduction.展开更多
Based on the special physical–chemical characteristics of optical crystal in the field of aeronautics,a new anhydrous based shear-thickening polishing(ASTP)method has been proposed to restrain deliquescence and to im...Based on the special physical–chemical characteristics of optical crystal in the field of aeronautics,a new anhydrous based shear-thickening polishing(ASTP)method has been proposed to restrain deliquescence and to improve physical properties for KDP machining.The ultraprecision polishing of KDP crystal is completed by ASTP.A kind of anhydrous based thickening polishing slurry(ATPS)was proposed in our work,and high-performance rheological properties were determined to achieve the ASTP of KDP crystal.A material removal model of ASTP in KDP machining is established,followed by the verification experiment of the prediction model.The maximum error of the predictive model is only 9.8%,which proves the validity of the material removal model for KDP polishing.The polishing experiments were carried out on the polishing platform developed by ourselves.The results show that the new polishing method can polish20 mm×20 mm×5 mm KDP crystal and obtain a super-smooth surface with a surface roughness of 1.37 nm and high shape accuracy.The surface accuracy of polished KDP crystal reaches up to0.68 k(RMS).The experimental results show that the ASTP is a potential ultra-precision machining method for KDP crystal.展开更多
The transmission line tower will be affected by bad weather and artificial subsidence caused by the foundation and other factors in the power transmission.The tower’s tilt and severe deformation will cause the buildi...The transmission line tower will be affected by bad weather and artificial subsidence caused by the foundation and other factors in the power transmission.The tower’s tilt and severe deformation will cause the building to collapse.Many small changes caused the tower’s collapse,but the early staff often could not intuitively notice the changes in the tower’s state.In the current tower online monitoring system,terminal equipment often needs to replace batteries frequently due to premature exhaustion of power.According to the need for real-time measurement of power line tower,this research designed a real-time monitoring device monitoring the transmission tower attitude tilting and foundation state based on the inertial sensor,the acceleration of 3 axis inertial sensor and angular velocity raw data to pole average filtering pre-processing,and then through the complementary filtering algorithm for comprehensive calculation of tilt angle,the system meets the demand for inclined online monitoring of power line poles and towers regarding measurement accuracy,with low cost and power consumption.The optimization multi-sensor cooperative detection and correction measured tilt angle result relative accuracy can reach 1.03%,which has specific promotion and application value since the system has the advantages of unattended and efficient calculation.展开更多
Understanding the assembly and spatial arrangement of bamboo cell wall components is crucial for its optimal utilization.Bamboo cell walls consist of aggregates of cellulose microfibrils and matrix.In the present stud...Understanding the assembly and spatial arrangement of bamboo cell wall components is crucial for its optimal utilization.Bamboo cell walls consist of aggregates of cellulose microfibrils and matrix.In the present study,the size and arrangement of cellulose microfibril aggregates in the cell walls of sclerenchyma fibers and parenchyma cells in moso bamboo were investigated with NMR and FE-SEM.The NMR measurement showed that the characteristic sizes of the microfibril aggregates of fibers and parenchyma cells were approximately 25.8 nm and 18.8 nm,respectively.Furthermore,high-resolution SEM showed the size of microfibril aggregates varied little across the cell wall of sclerenchyma fiber.However,there were significant size differences between the broad and narrow lamellae both in fiber and parenchyma cells,which is thought to be closely related to the orientation of microfibrils in these layers.The microfibril aggregates in the fibers mainly appear in a random arrangement,although occasionally in a radial or tangential arrangement in individual cell.Parenchyma cells have a relatively thinner cell wall layers,in which microfibril aggregates appear in a concentric lamellar arrangement.展开更多
The concept of optimal Delaunay triangulation (ODT) and the corresponding error-based quality metric are first introduced. Then one kind of mesh smoothing algorithm for tetrahedral mesh based on the concept of ODT is ...The concept of optimal Delaunay triangulation (ODT) and the corresponding error-based quality metric are first introduced. Then one kind of mesh smoothing algorithm for tetrahedral mesh based on the concept of ODT is examined. With regard to its problem of possible producing illegal elements, this paper proposes a modified smoothing scheme with a constrained optimization model for tetrahedral mesh quality improvement. The constrained optimization model is converted to an unconstrained one and then solved by integrating chaos search and BFGS (Broyden-Fletcher-Goldfarb-Shanno) algorithm efficiently. Quality improvement for tetrahedral mesh is finally achieved by alternately applying the presented smoothing scheme and re-triangulation. Some testing examples are given to demonstrate the effectiveness of the proposed approach.展开更多
Operating Room is an important place for surgical diagnosis and treatment and rescue of patients. With the rapid development of medical technology, high, precision, sharp continuous development, operating room safety ...Operating Room is an important place for surgical diagnosis and treatment and rescue of patients. With the rapid development of medical technology, high, precision, sharp continuous development, operating room safety management is particularly important. The error of the counting of the surgical articles causes the foreign body left in the patient’s body, which will cause irreversible damage to the patient and even cause the medical dispute and touch the legal problem. Operation items inventory system is an important working system in the operating room. Scientific and standardized methods and systems for counting surgical instruments and dressings during operation can prevent foreign bodies from being left in the body, prevent errors and accidents in the operating room, and are very important for ensuring the safety of the operation of patients. In order to ensure the safety of patients, it is necessary to ensure the correct inventory of surgical items. The factors affecting the accuracy of item counting in the operating room and the preventive measures are summarized as follows.展开更多
With the continuing demand for clean and sustainable energy storage devices,aqueous magnesium-ion capacitors have gained prominence as a viable electrochemical solution.However,highperformance aqueous magnesium-ion st...With the continuing demand for clean and sustainable energy storage devices,aqueous magnesium-ion capacitors have gained prominence as a viable electrochemical solution.However,highperformance aqueous magnesium-ion storage devices for energy need to satisfy rigorous requirements due to the large hydrated ionic radius of Mg^(2+) cations and the structural collapse of host materials during insertion/extraction.Herein,we propose a fluorine-mediated structural regulation strategy to design fluorine-mediated multivalent manganese oxide(F-m-MnO_(x))as cathode materials.By partially substituting oxygen sites with fluorine atoms,high-strength Mn-F bonds are formed within the MnO_(2) lattice,which locally enhance the framework stability by reinforcing the tunnel structure and effectively suppressing structural degradation during cycling.Furthermore,the robust Mn-F bond energy enables a unique“pinning effect”anchoring hydrothermally synthesized KMnF_(3) nanoparticles onto the MnO_(2) matrix.These KMnF_(3) nanoparticles act as dynamic bridges during Mg^(2+) insertion/extraction processes,with their surface-exposed chemically active sites facilitating transient yet reversible interactions with migrating Mg^(2+) ions.This innovative design significantly enhances Mg^(2+) diffusion kinetics through the bulk phase,offering a groundbreaking mechanism to overcome the inherent sluggish ion transport in multivalent cation systems.The F-m-MnO_(x) cathode delivers exceptional performance metrics:a high specific capacity of 142 mAh/g at 0.1 A/g,outstanding cycling stability(89.6%retention after 1800 cycles),and rapid kinetics.This research not only establishes an innovative design concept for advanced electrode materials through halogen-mediated structural engineering but also elucidates the dual magnesium-ion storage mechanism involving both KMnF_(3) and MnO_(2) in F-m-MnO_(x) through ex-situ characterization,enabling new possibilities for future clean energy storage.展开更多
Recently,a series of new measurements with both the neutral and charge current Drell–Yan processes have been performed at hadron colliders,revealing deviations from the predictions of the current parton distribution ...Recently,a series of new measurements with both the neutral and charge current Drell–Yan processes have been performed at hadron colliders,revealing deviations from the predictions of the current parton distribution functions(PDFs).In this article,the impact of these new measurements is studied by using their results to update the PDFs.Although these new measurements correspond to different boson propagators and colliding energies,they are found to have a similar impact to the light quark parton distributions with a momentum fraction x of approximately 0.1.The deviations are consistent with each other and favor a larger valence d_(v)/u_(v)ratio than the modern PDF predictions.Further study indicates that such tension results dominantly from the deep inelastic scattering measurements of NMC and the fixed target experiments of NuSea,both of which play pivotal roles in detecting the relative u-and d-type quark contributions for modern PDFs.The conclusions of the impact study indicate that these new measurements should be included in the complete PDF global analysis in the future.展开更多
Power electronics(PEs)play a pivotal role in electrical energy conversion and regulation for applications spanning from consumer devices to industrial infrastructure.Wide-bandgap(WBG)semiconductors such as SiC,GaN,and...Power electronics(PEs)play a pivotal role in electrical energy conversion and regulation for applications spanning from consumer devices to industrial infrastructure.Wide-bandgap(WBG)semiconductors such as SiC,GaN,and Ga2O3 have emerged as high-performance materials in PEs.Nevertheless,the WBG materials have some limitations that there exists the proliferation of intrinsic defects,with prohibitively high fabrication costs.We identify next-generation PEs materials beyond SiC,GaN,and Ga_(2)O_(3)based on a high-throughput computational methodology.A massive database affording 153,235 materials is screened by leveraging ab initio methods with the thorough evaluation of bandgap,electron mobility,thermal conductivity,and Baliga and Johnson figures of merit(BFOM and JFOM).The comprehensive and effective theoretical analysis identifies some promising candidates(B_(2)O_(3),BeO,and BN)that possess high BFOM,JFOM,and lattice thermal conductivity.Our methodology could be extended to other application domains of electronics,simplifying the process of exploring new materials.展开更多
The effects of alkaline treatment on the physical properties of ZSM-5 catalysts and on their activities for methanol to aromatics conversion have been investigated. A mild alkaline treatment （0.2 and 0.3 mol/L NaOH）...The effects of alkaline treatment on the physical properties of ZSM-5 catalysts and on their activities for methanol to aromatics conversion have been investigated. A mild alkaline treatment （0.2 and 0.3 mol/L NaOH） created mesopores in the parent zeolite with no obvious effect on acidity. The presence of mesopores gives the catalyst a longer lifetime and higher selectivity for aromatics. Treatment with 0.4 mol/L NaOH decreased the number of Bronsted acid sites due to dealumination and desilication, which resulted in a lower deactivation rate. In addition, more mesopores were produced than with the mild alkaline treatment. As a result, the lifetime of the sample treated with 0.4 mol/L NaOH was almost five times that of the parent ZSM-5. Treatment with a higher alkaline concentration （0.5 mol/L） greatly reduced the number of Bronsted acid sites and the number ofmicropores resulting in incomplete methanol conversion. When the alkalinetreated catalysts were washed with acid, some of the porosity was restored and a slight increase in selectivity for aromatics was obtained.展开更多
Programmed cell death 4 （PDCD4） is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer （CRC）. During CRC carcinogenesis, PDCD4 protein levels remarkably decrease...Programmed cell death 4 （PDCD4） is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer （CRC）. During CRC carcinogenesis, PDCD4 protein levels remarkably decrease, but the underlying molecular mechanism for decreased PDCD4 expression is not fully understood. In this study, we performed bioinformatics analysis to identify miRNAs that potentially target PDCD4. We demonstrated miR-181b as a direct regulator of PDCD4. We further showed that activation of IL6/STAT3 signaling pathway increased miR-181b expression and conse- quently resulted in downregulation of PDCD4 in CRC cells. In addition, we investigated the biological effects of PDCD4 inhibition by miR-181b both in vitro and in vivo and found that miR-181b could promote cell proliferation and migration and suppress apoptosis in CRC cells and accelerate tumor growth in xenograft mice, potentially through targeting PDCD4. Taken toge- ther, this study highlights an oncomiR role for miR-181b in regulating PDCD4 in CRC and suggests that miR-181b may be a novel molecular therapeutic target for CRC.展开更多
In this paper, we investigate the use of ultra weak variational formulation to solve a wave scattering problem in near field optics. In order to capture the sub-scale features of waves, we utilize evanescent wave func...In this paper, we investigate the use of ultra weak variational formulation to solve a wave scattering problem in near field optics. In order to capture the sub-scale features of waves, we utilize evanescent wave functions together with plane wave functions to approximate the local properties of the field. We analyze the global convergence and give an error estimation of the method. Numerical examples are also presented to demonstrate the effectiveness of the strategy.展开更多
The network structure of the smart substation in common use was introduced,and the technical problems of the shared-network of sampled measured value(SMV)and generic object oriented substation event(GOOSE)were analyze...The network structure of the smart substation in common use was introduced,and the technical problems of the shared-network of sampled measured value(SMV)and generic object oriented substation event(GOOSE)were analyzed,such as the processing ability of network device and the intelligent device,the data real-time property and the network reliability,the effects to the substation in the condition of network fault,etc.On this basis,the feasibility of the shared-network of SMV and GOOSE was discussed,the implement scheme was presented,and eventually the solution of the shared-network of SMV and GOOSE was put forward,which based on the applications of the message priority control,restricting the switch number,virtual local area network(VLAN)and GARP multicast registration protocol(GMRP)classification flow control,flow rate limiting,etc.In the test-bed,the cases of shared-network and separate-network of SMV and GOOSE were compared and analyzed,and the result was valuable for reference.展开更多
基金the National Natural Science Foundation of China(No.52374150)the Key Science and Technology Project of Ministry of Emergency Management of the People’s Republic of China(No.2024EMST141405).
文摘The stability of underground tunnel roofs is strongly influenced by wedge blocks formed by complex joint networks.The mechanical behavior and failure mechanisms of different roof wedge blocks in arched holes were investigated under biaxial stress conditions.The crack evolution and failure modes of the specimens were analyzed through acoustic emission(AE),digital image correlation(DIC),and discrete element method(DEM).Results show significant variations in mechanical properties:specimens T1(extremely unstable triangular)and T2(extremely unstable quadrilateral)exhibited higher strength than T3(extremely stable triangular)and T4(extremely stable quadrilateral),while support more effectively enhanced the strength of T3 and T4.Failure modes were classified as rock-dominated,wedgedominated,or co-dominated.Cracks typically initiated near the wedge and propagated outward.Unsupported specimens developed tensile cracks at the hole bottom,shear cracks at the sides,and mixed cracks along wedge boundaries,whereas supported specimens mainly exhibited cracks at the roof and sides.Stress analysis indicated that unsupported conditions induced high stress differences,promoting localized shear failure.Wedge geometry significantly affected shear stress redistribution at the roof.These findings highlight the critical role of support and wedge block geometry in controlling stress dis-tribution and failure mechanisms in arched tunnels.
基金supported by the National Natural Science Foundation of China(Nos.52071171,52202248)Liaoning BaiQianWan Talents Program(LNBQW2018B0048)+8 种基金Shenyang Science and Technology Project(21-108-9-04)Key Research Project of Department of Education of Liaoning Province(LJKZZ20220015)the Research Fund for the Doctoral Program of Liaoning Province(2022-BS-114)Chunhui Program of the Ministry of Education of the People’s Republic of China(202201135)Australian Research Council(ARC)through Future Fellowship(FT210100298,FT210100806)Discovery Project(DP220100603)Linkage Project(LP210100467,LP210200504,LP210200345,LP220100088)Industrial Transformation Training Centre(IC180100005)schemes,and the Australian Government through the Cooperative Research Centres Projects(CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA’s Transformative Research Accelerating Commercialisation Program(TM021).
文摘The advancement of aqueous magnesium ion energy storage devices encounters limitations due to the substantial hydration radius of magnesium ions(Mg^(2+))and their strong electrostatic interaction with the primary material.Consequently,this study successfully developed a MnS/MnO heterostructure through a straightforward hydrothermal and annealing method,marking its initial application in aqueous magnesium ion capacitors(AMICs).The fabricated MnS/MnO heterostructure,characterized by S defects,also generates Mn defects via in-situ initiation of early electrochemical processes.This unique dual ion defects MnS/MnO heterostructure(DID-MnS/MnO)enables the transformation of MnS and MnO,initially not highly active electrochemically for Mg^(2+),into cathode materials exhibiting high electrochemical activity and superior performance.Moreover,DID-MnS/MnO enhances conductivity,improves the kinetics of surface redox reactions,and increases the diffusion rate of Mg^(2+).Furthermore,this study introduces a dual energy storage mechanism for DID-MnS/MnO,which,in conjunction with dual ion defects,offers additional active sites for Mg^(2+)insertion/deinsertion in the host material,mitigating volume expansion and structural degradation during repeated charge-discharge cycles,thereby significantly enhancing cycling reversibility.As anticipated,using a three-electrode system,the developed DID-MnS/MnO demonstrated a discharge specific capacity of 237.9 mAh/g at a current density of 0.1 A/g.Remarkably,the constructed AMIC maintained a capacity retention rate of 94.3%after 10000 cycles at a current density of 1.0 A/g,with a specific capacitance of 165.7 F/g.Hence,DID-MnS/MnO offers insightful perspectives for designing alternative clean energy sources and is expected to contribute significantly to the advancement of the clean energy sector.
文摘Artificial photosynthesis is an ideal method for solar-to-chemical energy conversion,wherein solar energy is stored in the form of chemical bonds of solar fuels.In particular,the photocatalytic reduction of CO_(2)has attracted considerable attention due to its dual benefits of fossil fuel production and CO_(2)pollution reduction.However,CO_(2)is a comparatively stable molecule and its photoreduction is thermodynamically and kinetically challenging.Thus,the photocatalytic efficiency of CO_(2)reduction is far below the level of industrial applications.Therefore,development of low-cost cocatalysts is crucial for significantly decreasing the activation energy of CO_(2)to achieving efficient photocatalytic CO_(2)reduction.Herein,we have reported the use of a Ni_(2)P material that can serve as a robust cocatalyst by cooperating with a photosensitizer for the photoconversion of CO_(2).An effective strategy for engineering Ni_(2)P in an ultrathin layered structure has been proposed to improve the CO_(2)adsorption capability and decrease the CO_(2)activation energy,resulting in efficient CO_(2)reduction.A series of physicochemical characterizations including X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM),high-resolution transmission electron microscopy(HRTEM),and atomic force microscopy(AFM)were used to demonstrate the successful preparation of ultrathin Ni_(2)P nanosheets.The XRD and XPS results confirm the successful synthesis of Ni_(2)P from Ni(OH)2 by a low temperature phosphidation process.According to the TEM images,the prepared Ni_(2)P nanosheets exhibit a 2D and near-transparent sheet-like structure,suggesting their ultrathin thickness.The AFM images further demonstrated this result and also showed that the height of the Ni_(2)P nanosheets is ca 1.5 nm.The photoluminescence(PL)spectroscopy results revealed that the Ni_(2)P material could efficiently promote the separation of the photogenerated electrons and holes in[Ru(bpy)3]Cl2?6H2O.More importantly,the Ni_(2)P nanosheets could more efficiently promote the charge transfer and charge separation rate of[Ru(bpy)3]Cl2?6H2O compared with the Ni_(2)P particles.In addition,the electrochemical experiments revealed that the Ni_(2)P nanosheets,with their high active surface area and charge conductivity,can provide more active centers for CO_(2)conversion and accelerate the interfacial reaction dynamics.These results strongly suggest that the Ni_(2)P nanosheets are a promising material for photocatalytic CO_(2)reduction,and can achieve a CO generation rate of 64.8μmol·h^(-1),which is 4.4 times higher than that of the Ni_(2)P particles.In addition,the XRD and XPS measurements of the used Ni_(2)P nanosheets after the six cycles of the photocatalytic CO_(2)reduction reaction demonstrated their high stability.Overall,this study offers a new function for the 2D transition-metal phosphide catalysts in photocatalytic CO_(2)reduction.
基金supported by the National Basic Research Program of China(‘‘973’’Program,No.2013CB035906)Foundation for Innovative Research Groups of the National Natural Science Foundation of China(No.51621092)Heilongjiang Provincial Major Scientific and Technological Project of Applied Technology Research and Development Plan(No.GA14A501)
基金supported by the National Basic Research Program of China (‘‘973’’ Program, No. 2013CB035906)the National Natural Science Foundation of China (No. 51439005)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 51621092)
基金the National Natural Science Foundation of China(No.51605163)Alexander von Humboldt Foundation of Germany(2019)+1 种基金Hunan Provincial Key R&D Project(No.GK2050)Zhejiang Provincial Natural Science Foundation(No.LR17E050002)。
文摘Based on the special physical–chemical characteristics of optical crystal in the field of aeronautics,a new anhydrous based shear-thickening polishing(ASTP)method has been proposed to restrain deliquescence and to improve physical properties for KDP machining.The ultraprecision polishing of KDP crystal is completed by ASTP.A kind of anhydrous based thickening polishing slurry(ATPS)was proposed in our work,and high-performance rheological properties were determined to achieve the ASTP of KDP crystal.A material removal model of ASTP in KDP machining is established,followed by the verification experiment of the prediction model.The maximum error of the predictive model is only 9.8%,which proves the validity of the material removal model for KDP polishing.The polishing experiments were carried out on the polishing platform developed by ourselves.The results show that the new polishing method can polish20 mm×20 mm×5 mm KDP crystal and obtain a super-smooth surface with a surface roughness of 1.37 nm and high shape accuracy.The surface accuracy of polished KDP crystal reaches up to0.68 k(RMS).The experimental results show that the ASTP is a potential ultra-precision machining method for KDP crystal.
基金This work was supported by the National Natural Science Foundation of China(Nos.62172242,51901152)Industry University Cooperation Education Program of the Ministry of Education(No.2020021680113)Shanxi Scholarship Council of China.
文摘The transmission line tower will be affected by bad weather and artificial subsidence caused by the foundation and other factors in the power transmission.The tower’s tilt and severe deformation will cause the building to collapse.Many small changes caused the tower’s collapse,but the early staff often could not intuitively notice the changes in the tower’s state.In the current tower online monitoring system,terminal equipment often needs to replace batteries frequently due to premature exhaustion of power.According to the need for real-time measurement of power line tower,this research designed a real-time monitoring device monitoring the transmission tower attitude tilting and foundation state based on the inertial sensor,the acceleration of 3 axis inertial sensor and angular velocity raw data to pole average filtering pre-processing,and then through the complementary filtering algorithm for comprehensive calculation of tilt angle,the system meets the demand for inclined online monitoring of power line poles and towers regarding measurement accuracy,with low cost and power consumption.The optimization multi-sensor cooperative detection and correction measured tilt angle result relative accuracy can reach 1.03%,which has specific promotion and application value since the system has the advantages of unattended and efficient calculation.
基金The authors gratefully acknowledge the National Natural Science Foundation(31770600)for its financial support.
文摘Understanding the assembly and spatial arrangement of bamboo cell wall components is crucial for its optimal utilization.Bamboo cell walls consist of aggregates of cellulose microfibrils and matrix.In the present study,the size and arrangement of cellulose microfibril aggregates in the cell walls of sclerenchyma fibers and parenchyma cells in moso bamboo were investigated with NMR and FE-SEM.The NMR measurement showed that the characteristic sizes of the microfibril aggregates of fibers and parenchyma cells were approximately 25.8 nm and 18.8 nm,respectively.Furthermore,high-resolution SEM showed the size of microfibril aggregates varied little across the cell wall of sclerenchyma fiber.However,there were significant size differences between the broad and narrow lamellae both in fiber and parenchyma cells,which is thought to be closely related to the orientation of microfibrils in these layers.The microfibril aggregates in the fibers mainly appear in a random arrangement,although occasionally in a radial or tangential arrangement in individual cell.Parenchyma cells have a relatively thinner cell wall layers,in which microfibril aggregates appear in a concentric lamellar arrangement.
文摘The concept of optimal Delaunay triangulation (ODT) and the corresponding error-based quality metric are first introduced. Then one kind of mesh smoothing algorithm for tetrahedral mesh based on the concept of ODT is examined. With regard to its problem of possible producing illegal elements, this paper proposes a modified smoothing scheme with a constrained optimization model for tetrahedral mesh quality improvement. The constrained optimization model is converted to an unconstrained one and then solved by integrating chaos search and BFGS (Broyden-Fletcher-Goldfarb-Shanno) algorithm efficiently. Quality improvement for tetrahedral mesh is finally achieved by alternately applying the presented smoothing scheme and re-triangulation. Some testing examples are given to demonstrate the effectiveness of the proposed approach.
文摘Operating Room is an important place for surgical diagnosis and treatment and rescue of patients. With the rapid development of medical technology, high, precision, sharp continuous development, operating room safety management is particularly important. The error of the counting of the surgical articles causes the foreign body left in the patient’s body, which will cause irreversible damage to the patient and even cause the medical dispute and touch the legal problem. Operation items inventory system is an important working system in the operating room. Scientific and standardized methods and systems for counting surgical instruments and dressings during operation can prevent foreign bodies from being left in the body, prevent errors and accidents in the operating room, and are very important for ensuring the safety of the operation of patients. In order to ensure the safety of patients, it is necessary to ensure the correct inventory of surgical items. The factors affecting the accuracy of item counting in the operating room and the preventive measures are summarized as follows.
基金supported by the National Natural Science Foundation of China(Nos.52071171 and 52202248)Key Research Project of Department of Education of Liaoning Province(No.LJKZZ20220015)+11 种基金Liaoning University Youth Research Fund project(No.LDZDJB2302)Fundamental Research Funds for Public Universities in Liaoning(No.LJKLJ202425)Natural Science Foundation of Liaoning Province(No.2024-MS-007)Natural Science Foundation of Liaoning Province(No.2024-MSLH-184)Natural Science Foundation of Yingkou City(No.YKSCJH2024-025)Fundamental Research Funds for Public Universities in Liaoning(Nos.LJ232410140033 and LJ242510140014)Advanced Plan Project of Liaoning Province(No.2023JH2/1060014).T.Y.M.acknowledged the Australian Research Council(ARC)through Future Fellowship(No.FT210100298)Discovery Project(No.DP220100603)Linkage Project(Nos.LP210200504,LP220100088,and LP230200897)Industrial Transformation Research Hub(No.IH240100009)schemes,the Australian Government through the Cooperative Research Centres Projects(No.CRCPXIII000077)the Australian Renewable Energy Agency(ARENA)as part of ARENA’s Transformative Research Accelerating Commercialisation Program(No.TM021)European Commission’s Australia-Spain Network for Innovation and Research Excellence(AuSpire).
文摘With the continuing demand for clean and sustainable energy storage devices,aqueous magnesium-ion capacitors have gained prominence as a viable electrochemical solution.However,highperformance aqueous magnesium-ion storage devices for energy need to satisfy rigorous requirements due to the large hydrated ionic radius of Mg^(2+) cations and the structural collapse of host materials during insertion/extraction.Herein,we propose a fluorine-mediated structural regulation strategy to design fluorine-mediated multivalent manganese oxide(F-m-MnO_(x))as cathode materials.By partially substituting oxygen sites with fluorine atoms,high-strength Mn-F bonds are formed within the MnO_(2) lattice,which locally enhance the framework stability by reinforcing the tunnel structure and effectively suppressing structural degradation during cycling.Furthermore,the robust Mn-F bond energy enables a unique“pinning effect”anchoring hydrothermally synthesized KMnF_(3) nanoparticles onto the MnO_(2) matrix.These KMnF_(3) nanoparticles act as dynamic bridges during Mg^(2+) insertion/extraction processes,with their surface-exposed chemically active sites facilitating transient yet reversible interactions with migrating Mg^(2+) ions.This innovative design significantly enhances Mg^(2+) diffusion kinetics through the bulk phase,offering a groundbreaking mechanism to overcome the inherent sluggish ion transport in multivalent cation systems.The F-m-MnO_(x) cathode delivers exceptional performance metrics:a high specific capacity of 142 mAh/g at 0.1 A/g,outstanding cycling stability(89.6%retention after 1800 cycles),and rapid kinetics.This research not only establishes an innovative design concept for advanced electrode materials through halogen-mediated structural engineering but also elucidates the dual magnesium-ion storage mechanism involving both KMnF_(3) and MnO_(2) in F-m-MnO_(x) through ex-situ characterization,enabling new possibilities for future clean energy storage.
基金Supported by the National Natural Science Foundation of China(12061141005,12105275)。
文摘Recently,a series of new measurements with both the neutral and charge current Drell–Yan processes have been performed at hadron colliders,revealing deviations from the predictions of the current parton distribution functions(PDFs).In this article,the impact of these new measurements is studied by using their results to update the PDFs.Although these new measurements correspond to different boson propagators and colliding energies,they are found to have a similar impact to the light quark parton distributions with a momentum fraction x of approximately 0.1.The deviations are consistent with each other and favor a larger valence d_(v)/u_(v)ratio than the modern PDF predictions.Further study indicates that such tension results dominantly from the deep inelastic scattering measurements of NMC and the fixed target experiments of NuSea,both of which play pivotal roles in detecting the relative u-and d-type quark contributions for modern PDFs.The conclusions of the impact study indicate that these new measurements should be included in the complete PDF global analysis in the future.
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(grant number:15233823)the Research Institute for Advanced Manufacturing of the Hong Kong Polytechnic University(project code:1-CDJV).
文摘Power electronics(PEs)play a pivotal role in electrical energy conversion and regulation for applications spanning from consumer devices to industrial infrastructure.Wide-bandgap(WBG)semiconductors such as SiC,GaN,and Ga2O3 have emerged as high-performance materials in PEs.Nevertheless,the WBG materials have some limitations that there exists the proliferation of intrinsic defects,with prohibitively high fabrication costs.We identify next-generation PEs materials beyond SiC,GaN,and Ga_(2)O_(3)based on a high-throughput computational methodology.A massive database affording 153,235 materials is screened by leveraging ab initio methods with the thorough evaluation of bandgap,electron mobility,thermal conductivity,and Baliga and Johnson figures of merit(BFOM and JFOM).The comprehensive and effective theoretical analysis identifies some promising candidates(B_(2)O_(3),BeO,and BN)that possess high BFOM,JFOM,and lattice thermal conductivity.Our methodology could be extended to other application domains of electronics,simplifying the process of exploring new materials.
文摘The effects of alkaline treatment on the physical properties of ZSM-5 catalysts and on their activities for methanol to aromatics conversion have been investigated. A mild alkaline treatment （0.2 and 0.3 mol/L NaOH） created mesopores in the parent zeolite with no obvious effect on acidity. The presence of mesopores gives the catalyst a longer lifetime and higher selectivity for aromatics. Treatment with 0.4 mol/L NaOH decreased the number of Bronsted acid sites due to dealumination and desilication, which resulted in a lower deactivation rate. In addition, more mesopores were produced than with the mild alkaline treatment. As a result, the lifetime of the sample treated with 0.4 mol/L NaOH was almost five times that of the parent ZSM-5. Treatment with a higher alkaline concentration （0.5 mol/L） greatly reduced the number of Bronsted acid sites and the number ofmicropores resulting in incomplete methanol conversion. When the alkalinetreated catalysts were washed with acid, some of the porosity was restored and a slight increase in selectivity for aromatics was obtained.
文摘Programmed cell death 4 （PDCD4） is a RNA-binding protein that acts as a tumor suppressor in many cancer types, including colorectal cancer （CRC）. During CRC carcinogenesis, PDCD4 protein levels remarkably decrease, but the underlying molecular mechanism for decreased PDCD4 expression is not fully understood. In this study, we performed bioinformatics analysis to identify miRNAs that potentially target PDCD4. We demonstrated miR-181b as a direct regulator of PDCD4. We further showed that activation of IL6/STAT3 signaling pathway increased miR-181b expression and conse- quently resulted in downregulation of PDCD4 in CRC cells. In addition, we investigated the biological effects of PDCD4 inhibition by miR-181b both in vitro and in vivo and found that miR-181b could promote cell proliferation and migration and suppress apoptosis in CRC cells and accelerate tumor growth in xenograft mice, potentially through targeting PDCD4. Taken toge- ther, this study highlights an oncomiR role for miR-181b in regulating PDCD4 in CRC and suggests that miR-181b may be a novel molecular therapeutic target for CRC.
基金The authors would like to thank the reviewers and Dr.Zheng Enxi for many valuable suggcstions. This work is supported by the National Natural Science Foundation of China （Grant No. 11371172, 51178001）, Science and technology research project of the education department of Jilin Province （Grant No. 2014213）.
文摘In this paper, we investigate the use of ultra weak variational formulation to solve a wave scattering problem in near field optics. In order to capture the sub-scale features of waves, we utilize evanescent wave functions together with plane wave functions to approximate the local properties of the field. We analyze the global convergence and give an error estimation of the method. Numerical examples are also presented to demonstrate the effectiveness of the strategy.
文摘The network structure of the smart substation in common use was introduced,and the technical problems of the shared-network of sampled measured value(SMV)and generic object oriented substation event(GOOSE)were analyzed,such as the processing ability of network device and the intelligent device,the data real-time property and the network reliability,the effects to the substation in the condition of network fault,etc.On this basis,the feasibility of the shared-network of SMV and GOOSE was discussed,the implement scheme was presented,and eventually the solution of the shared-network of SMV and GOOSE was put forward,which based on the applications of the message priority control,restricting the switch number,virtual local area network(VLAN)and GARP multicast registration protocol(GMRP)classification flow control,flow rate limiting,etc.In the test-bed,the cases of shared-network and separate-network of SMV and GOOSE were compared and analyzed,and the result was valuable for reference.
