According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expound...According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expounded. Six spark program systems were established,consisting of policy support guide,science and technology project lead,experts' intelligence support,spark science and technology training,scitech information service and spark program demonstration. Five spark projects were implemented to promote new rural construction in the west bank of Taiwan Strait,such as constructing the national spark industrial zone,organizing the new rural construction led by science and technology,constituting spark sci-tech innovation center,developing the rural informatization,and establishing science and technology commissioner bases. Finally,enlightenment of spark program and its development ways in the future were put forward.展开更多
To analysis the early failures of machining centers,the failure mode effect and criticality analysis( FMECA) method was used. Based on the failure data collected from production lines in test run,all the failure modes...To analysis the early failures of machining centers,the failure mode effect and criticality analysis( FMECA) method was used. Based on the failure data collected from production lines in test run,all the failure modes of machining centers were summarized and criticality of all subsystems is figured out. And the process of FMECA was improved. The most critical subsystem was manipulator subsystem. The most critical failure mode was impacted manipulator. Reasons and effect of some important failure modes were analyzed. And some suggestions to solve failures were given.展开更多
Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an import...Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an important role for the new concept missile design. This paper describes the detailed definition of RSS and its advantages, pres- ents the research status and prospects for its application in the design of new missiles.展开更多
As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and com...As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the laboratory.The results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 mm.After improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 kPa.By using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 kPa.The bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 mm.After optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.展开更多
Objective To establish a scientific,reliable,objective,and effective clinical comprehensive evaluation system for drugs centralized bidding procurement by government,and to conduct reliability and validity test and em...Objective To establish a scientific,reliable,objective,and effective clinical comprehensive evaluation system for drugs centralized bidding procurement by government,and to conduct reliability and validity test and empirical analysis of the evaluation index system through simulated measurement.Methods Literature research method was used to select comprehensive evaluation indicators for drugs centralized bidding procurement.Then,Dephi method was applied to screen the final evaluation indicators,and the weight of the indicators was determined using analytic hierarchy process.Results and Conclusion The final clinical efficacy evaluation index system for drugs centralized bidding procurement includes 5 primary indicators and 13 secondary indicators.The experts authority coefficient in this study is high,and their opinions relatively coincide.Through the empirical research,the reliability and structural validity of the indicator system is good.This indicator system enriches methods and tools for scientifically evaluating the clinical efficacy of drugs centralized bidding procurement.展开更多
Non-alcoholic fatty liver disease(NAFLD)has emerged as a global public health concern,affecting over one-quarter of the global population.It is closely associated with the prevalence of obesity and metabolic syndrome....Non-alcoholic fatty liver disease(NAFLD)has emerged as a global public health concern,affecting over one-quarter of the global population.It is closely associated with the prevalence of obesity and metabolic syndrome.Current treatment options for NAFLD are limited and often have side effects.Traditional Chinese medicine(TCM)offers a promising alternative with its holistic approach and use of multi-component herbal formulations.A recent study explored the potential of the TCM formula,"Fanlian Huazhuo Formula(FLHZF)",to alleviate high-fat dietinduced NAFLD by regulating autophagy and lipid synthesis signaling pathways.TCM has shown advantages in the prevention and treatment of NAFLD due to its efficacy and minimal side effects.However,the complex multicomponent and multitarget characteristics of formulas such as FLHZF present challenges in research.Future studies should focus on utilizing modern techniques to deepen our understanding of the mechanisms of action and active ingredients of Chinese herbal medicines,thereby promoting their modernization.展开更多
The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were syst...The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were systematically investigated.The results show that gradient nanostructures are formed on the surface of Ni-W-Co-Ta MHA after SFPB treatment.At a gas pressure of 1.0 MPa and an impact time of 60 s,the ultimate tensile strength and yield strength of the alloy reached the maximum values of 1236 MPa and 758 MPa,respectively,which are 22.5%and 38.8%higher than those of the solid solution treated alloy,and the elongation(46.3%)is close to that of the solid solution treated alloy,achieving the optimal strength–ductility synergy.However,microcracks appear on the surface with excessive gas pressure and impact time,generating the relaxed residual stress and decreased strength.With the increase of the impact time and gas pressure,the depth of the deformation layer and the surface microhardness gradually increase,reaching the maximum values(29μm and HV 451)at 1.0 MPa and 120 s.The surface grain size is refined to a minimum of 11.67 nm.Notably,SFPB treatment has no obvious effect on elongation,and the fracture mode changes from the ductile fracture before treatment to ductile–brittle mixed fracture after treatment.展开更多
Lake ecosystems are extremely sensitive to nitrogen growth,which leads to water quality degradation and ecosystem health decline.Nitrogen depositions,as one of the main sources of nitrogen in water,are expected to cha...Lake ecosystems are extremely sensitive to nitrogen growth,which leads to water quality degradation and ecosystem health decline.Nitrogen depositions,as one of the main sources of nitrogen in water,are expected to change under future climate change scenarios.However,it remains not clear how nitrogen deposition to lakes respond to future meteorological conditions.In this study,a source-oriented version of Community Multiscale Air Quality(CMAQ)Model was used to estimate nitrogen deposition to 263 lakes in 2013 and under three RCP scenarios(4.5,6.0 and 8.5)in 2046.Annual total deposition of 58.2 Gg nitrogen was predicted for all lakes,with 23.3 Gg N by wet deposition and 34.9 Gg N by dry deposition.Nitrate and ammonium in aerosol phase are the major forms of wet deposition,while NH3 and HNO_(3)in gas phase are the major forms of dry deposition.Agriculture emissions contribute to 57%of wet deposition and 44%of dry deposition.Under future meteorological conditions,wet deposition is predicted to increase by 5.5%to 16.4%,while dry deposition would decrease by 0.3%to 13.0%.Changes in wind speed,temperature,relative humidity(RH),and precipitation rates are correlated with dry and wet deposition changes.The predicted changes in deposition to lakes driven by meteorological changes can lead to significant changes in aquatic chemistry and ecosystem functions.Apart from future emission scenarios,different climate scenarios should be considered in future ecosystem health evaluation in response to nitrogen deposition.展开更多
This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shea...This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.展开更多
The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model unce...The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model uncertain, is much more complex than conventional nero-fin control. A novel nonlinear backstepping control approach is proposed to design the blended autopilot. Missile model is reformed to a new one by state reconstruction technique so that it is easy to be handled by the backstepping method. Then a Lyapunov function is chosen to avoid oscillation caused in normal backstepping way when control parameters are mismatched. In distribution of both inputs, optimal energy logic is proposed. In addition, a fuzzy cerebellar model articulation controller （FCMAC） neural network is used to guarantee controller robustness to uncertainties. Finally, simulation results demonstrate the efficiency and advantages of the proposed method.展开更多
Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provi...Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provide broader spectra of resistances in wheat improvement. A new powdery mildew resistance gene originating from wild emmer(Triticum turgidum var.dicoccoides) backcrossed into common wheat(T. aestivum) line WE35 was identified. It conferred an intermediate level of resistance to Blumeria graminis f. sp. tritici isolate E09 at the seedling stage and a high level of resistance at the adult plant stage. Genetic analysis showed that the powdery mildew resistance in WE35 was controlled by a dominant gene designated Pm64. Bulked segregant analysis(BSA) and molecular mapping indicated that Pm64 was located in chromosome bin 2 BL4-0.50–0.89. Polymorphic markers were developed from the corresponding genomic regions of Chinese Spring wheat and wild emmer accession Zavitan to delimit Pm64 to a 0.55 cM genetic interval between markers WGGBH1364 and WGGBH612, corresponding to a 15 Mb genomic region on Chinese Spring and Zavitan 2 BL, respectively. The genetic linkage map of Pm64 is critical for fine mapping and cloning. Pm64 was completely linked in repulsion with stripe rust resistance gene Yr5. Analysis of a larger segregating population might identify a recombinant line with both genes as a valuable resource in breeding for resistance to powdery mildew and stripe rust.展开更多
The airborne missile launch mechanism often subjects to significant deformations induced by the large ejection force during high-speed actuations in missile ejection process,leading to a substantial deviation of separ...The airborne missile launch mechanism often subjects to significant deformations induced by the large ejection force during high-speed actuations in missile ejection process,leading to a substantial deviation of separation parameters from designed values that threats safety of the carrier.This study proposes a novel variable topology design for launch mechanism,achieved via a Prsmatic-Revolute-Revolute pair(PR-R)motion formed by the structural gap with a specific direction.It enables launch mechanism variability during missile ejection process and optimizes the ejection force given by the front and back ejection arms,and greatly optimizes the separation parameters during missile ejection.The kinetics simulation analysis is conducted under working conditions of the original ejection mechanism and the novel mechanism with variable topology design,respectively.The results show that the novel variable topology design is more befitting for the launch process in terms of system safety and controllability,effectively improving the separation posture,restraining the flexible effect of the mechanism,and fulfilling the effectiveness of the design value of multi-rigid body.展开更多
Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,t...Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).展开更多
The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）...The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）. Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays （i.e., microplates, membranes, gels, and chips） as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.展开更多
This paper investigates the robust formation control for missiles with obstacle avoidance.A sliding mode surface that is asymptotically stable is firstly presented by the collision avoidance potential function and hyp...This paper investigates the robust formation control for missiles with obstacle avoidance.A sliding mode surface that is asymptotically stable is firstly presented by the collision avoidance potential function and hyperbolic tangent function.Based on the sliding mode surface,a robust formation controller with obstacle avoidance is designed for missiles.To improve the convergence rate,a finite-time controller which can deal with the formation control for missiles is given using an improved sliding mode surface.Finally,the effectiveness of the designed controllers for missiles is demonstrated by the Lyapunov theory and simulation results.展开更多
Adult Chrysoperla sinica Tjeder is a common pollen feeder in maize fields. They are thus directly exposed to insecticidal proteins by consumption of genetically engineered maize pollen containing Bacillus thuringiensi...Adult Chrysoperla sinica Tjeder is a common pollen feeder in maize fields. They are thus directly exposed to insecticidal proteins by consumption of genetically engineered maize pollen containing Bacillus thuringiensis(Bt) proteins. Here we assessed the potential effects of Cry1 Ab/2 Aj-or Cry1 Ac-containing Bt maize pollen on the fitness of adult C. sinica via a dietary-exposure assay under laboratory conditions. Survival, pre-oviposition, fecundity and adult dry weight did not differ between adult C. sinica consuming Bt or the corresponding non-Bt maize pollen. The stability of the Cry protein in the food sources and uptake of the Cry protein by adult C. sinica during the feeding experiment were confirmed by ELISA. These results demonstrate that adult C. sinica are not affected by the consumption of Cry1 Ab/2 Aj-or Cry1 Ac-containing maize pollen, suggesting that production of Bt maize expressing cry1 Ab/2 Aj or cry1 Ac genes will pose a negligible risk to adult C. sinica.展开更多
The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion ...The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion techniques to investigate the diffusion behavior of HTO and ^(99)TcO_4^- on GMZ bentonite of various densities. Diffusion rates were calculated by measuring the diffusion coefficients(De, Da), plotting breakthrough curves and interpreting experiment data. The apparent and effective diffusion coefficients of HTO ranged from(1.68 ± 0.40) 9 × 10^(-11) to(2.80 ± 0.62) 9 × 10^(-11) m^2/s and from(4.61 ±1.28) 9 × 10^(-12) to (16.2 ± 2.50) 9 × 10^(-12) m^2/s, respectively.The apparent and effective diffusion coefficients of^(99)TcO_4^-ranged from(5.26 ± 0.16) 9 × 10^-12to(7.78 ± 0.43) 9× 10^-12m^2/s and from(1.49 ± 0.002) 9 × 10^(-12) to(4.16 ±0.07) 9 × 10^(-12) m^2/s, respectively. The distribution coefficients of HTO and^(99)TcO_4^-ranged from(0.70 ± 0.12) 9× 10^(-2) to(1.36 ± 0.53) 9 × 10^(-2) mL/g and from(1.12 ±0.06) 9 × 10^(-2) to(5.79 ± 2.22) 9 × 10^(-2) mL/g, respectively.The Deand Kdvalues were shown to decrease with an increase in the bulk dry density of compacted bentonite. Our results show that HTO and ^(99)Tc could be considered nonsorbent radionuclides. The data obtained in this studyprovide a valuable reference for the safety assessment of waste repositories.展开更多
This study focuses on the thermo-mechanical properties of Carbon Fibre/Polyimide Composite(CFPC)attaching collars under transient heating.The CFPC attaching collars were fabricated by a high-temperature resin transfer...This study focuses on the thermo-mechanical properties of Carbon Fibre/Polyimide Composite(CFPC)attaching collars under transient heating.The CFPC attaching collars were fabricated by a high-temperature resin transfer moulding process,and their thermo-mechanical properties under the conditions of simultaneous transient heating and bending load were investigated.The results show that the attaching collar tends to fail at 118% of the limit load.The failure mode includes the fracture of the connecting screws,local extrusion damage of the hole edges,and slight ablation damage at the outer plies.And there is no observable residual deformation in the composite attaching collar.Furthermore,considering that the material properties vary with temperature,a progressive damage model based on the sequential thermo-mechanical coupling method was established to study the failure mechanism of the attaching collar.Finally,the damage factor of the CFPC was calculated to assess the safety status of the attaching collar.The results show that the primary damage modes of the composite attaching collar are intralaminar failure,which mainly occurs at the heat insulation layer and the hole edges,and these slightly affect the structural bearing capacity.A good correlation between the experiment and FEA is obtained.The test methods and analysis models proposed contribute to the safety assessment of composite structures under transient heating.展开更多
The ever-growing market of wearable electronic devices has greatly stimulated the rapid development of flexible Zn-ion batteries(ZIBs).Manganese oxides are one of the most commonly used hosts for zinc ion accommodatio...The ever-growing market of wearable electronic devices has greatly stimulated the rapid development of flexible Zn-ion batteries(ZIBs).Manganese oxides are one of the most commonly used hosts for zinc ion accommodation and thus receive particular research interest for high-performance flexible ZIB constructions.In this review,a comprehensive summary of the recent development of flexible ZIBs with manganese oxides as cathode materials is presented.Apart from the brief introduction of flexible electronic devices and ZIBs,the charge storage mechanisms and crystal structures of various manganese oxides are summarized.Modifications of the cathode materials in terms of morphology,conductivity,structures,and flexibilities are illustrated in detail,together with the demonstration of structure-performance relationships and applications in flexible ZIBs.Finally,limitations to be overcome are indicated and the future work directions are proposed.展开更多
基金Supported by the Regional Science and Technology Project of Fujian Province,China(2009N3007)Science and Technology Project of Quanzhou City,Fujian Province,China(2008ZD11-1)12396 Multimedia Information Remote Service Platform Construction of Spark Science and Technology for Quanzhou City,Fujian Province,China(2008ZD15,2011ZD04N01)
文摘According to practice and exploration of spark program for 26 years in Quanzhou,the main model and their effects of new rural construction in west bank of Taiwan Strait led by spark science and technology were expounded. Six spark program systems were established,consisting of policy support guide,science and technology project lead,experts' intelligence support,spark science and technology training,scitech information service and spark program demonstration. Five spark projects were implemented to promote new rural construction in the west bank of Taiwan Strait,such as constructing the national spark industrial zone,organizing the new rural construction led by science and technology,constituting spark sci-tech innovation center,developing the rural informatization,and establishing science and technology commissioner bases. Finally,enlightenment of spark program and its development ways in the future were put forward.
基金National Science and Technology Major Project of China(No.2013ZX04012071)
文摘To analysis the early failures of machining centers,the failure mode effect and criticality analysis( FMECA) method was used. Based on the failure data collected from production lines in test run,all the failure modes of machining centers were summarized and criticality of all subsystems is figured out. And the process of FMECA was improved. The most critical subsystem was manipulator subsystem. The most critical failure mode was impacted manipulator. Reasons and effect of some important failure modes were analyzed. And some suggestions to solve failures were given.
文摘Relaxed Stable Stability （RSS） in an important part of the active control technology. It is a new way to raise the flying speed, distance and maneuverability of missile. Depth study of RSS technology plays an important role for the new concept missile design. This paper describes the detailed definition of RSS and its advantages, pres- ents the research status and prospects for its application in the design of new missiles.
基金supported by the Basic Science Center Project for the National Natural Science Foundation of China(No.72088101)the S&T Program of Hebei(No.23564101D).
文摘As the bed depth increases,sintering yield increases,but the productivity decreases.To reveal the reasons for the decrease in productivity and explore targeted solutions,the bed resistance of mixtures,wet zone,and combustion zone was analyzed in the laboratory.The results showed that the decreased porosity of mixture resulted in the increased bed resistance by 160.56%when the bed depth increased from 600 to 1000 mm.After improving porosity of 1%by adding loosening bars with optimized size and distribution,the bed resistance decreased,and the productivity increased by 5%.The increase in bed depth increased the thickness of the wet zone from 120 to 680 mm and the resistance from 1.56 to 8.83 kPa.By using a three-stage intensive mixer and pre-adding water for granulation,the moisture of mixture was reduced by 0.6%,and the sintering productivity increased by 4%.Besides,the high bed resistance is mainly caused by the increase in the thickness of the combustion zone from 31.9 to 132.7 mm,and the bed resistance increased from 0.70 to 5.62 kPa.The bed resistance of the combustion zone at 900 mm was increased by 90.51%compared to 700 mm.After optimization of the distribution of coke breeze,the thickness of combustion zone at the lower layer decreased from 132.7 to 106.84 mm and permeability improved significantly.
文摘Objective To establish a scientific,reliable,objective,and effective clinical comprehensive evaluation system for drugs centralized bidding procurement by government,and to conduct reliability and validity test and empirical analysis of the evaluation index system through simulated measurement.Methods Literature research method was used to select comprehensive evaluation indicators for drugs centralized bidding procurement.Then,Dephi method was applied to screen the final evaluation indicators,and the weight of the indicators was determined using analytic hierarchy process.Results and Conclusion The final clinical efficacy evaluation index system for drugs centralized bidding procurement includes 5 primary indicators and 13 secondary indicators.The experts authority coefficient in this study is high,and their opinions relatively coincide.Through the empirical research,the reliability and structural validity of the indicator system is good.This indicator system enriches methods and tools for scientifically evaluating the clinical efficacy of drugs centralized bidding procurement.
文摘Non-alcoholic fatty liver disease(NAFLD)has emerged as a global public health concern,affecting over one-quarter of the global population.It is closely associated with the prevalence of obesity and metabolic syndrome.Current treatment options for NAFLD are limited and often have side effects.Traditional Chinese medicine(TCM)offers a promising alternative with its holistic approach and use of multi-component herbal formulations.A recent study explored the potential of the TCM formula,"Fanlian Huazhuo Formula(FLHZF)",to alleviate high-fat dietinduced NAFLD by regulating autophagy and lipid synthesis signaling pathways.TCM has shown advantages in the prevention and treatment of NAFLD due to its efficacy and minimal side effects.However,the complex multicomponent and multitarget characteristics of formulas such as FLHZF present challenges in research.Future studies should focus on utilizing modern techniques to deepen our understanding of the mechanisms of action and active ingredients of Chinese herbal medicines,thereby promoting their modernization.
基金supported by the National key Research and Development Program of China(No.2022YFB3705200)the National Natural Science Foundation of China(Nos.U1804146,51905153,52111530068)+1 种基金the Science and Technology Innovation Team Project of Henan University of Science and Technology,China(No.2015XTD006)the Major Science and Technology Project of Henan Province,China(No.221100230200)。
文摘The effects of gradient nanostructures induced by supersonic fine particle bombardment(SFPB)on the surface integrity,microstructural evolution,and mechanical properties of a Ni-W-Co-Ta medium-heavy alloy(MHA)were systematically investigated.The results show that gradient nanostructures are formed on the surface of Ni-W-Co-Ta MHA after SFPB treatment.At a gas pressure of 1.0 MPa and an impact time of 60 s,the ultimate tensile strength and yield strength of the alloy reached the maximum values of 1236 MPa and 758 MPa,respectively,which are 22.5%and 38.8%higher than those of the solid solution treated alloy,and the elongation(46.3%)is close to that of the solid solution treated alloy,achieving the optimal strength–ductility synergy.However,microcracks appear on the surface with excessive gas pressure and impact time,generating the relaxed residual stress and decreased strength.With the increase of the impact time and gas pressure,the depth of the deformation layer and the surface microhardness gradually increase,reaching the maximum values(29μm and HV 451)at 1.0 MPa and 120 s.The surface grain size is refined to a minimum of 11.67 nm.Notably,SFPB treatment has no obvious effect on elongation,and the fracture mode changes from the ductile fracture before treatment to ductile–brittle mixed fracture after treatment.
基金supported by the project of Guangzhou Institute of Geochemistry the Chinese Academy of Sciences(No.51TGC202209)Shenzhen Science and Technology Plan(Nos.KJYY20180206180737010 and 6020320003K)the National Key R&D Program of China(No.2022YFC3701105).
文摘Lake ecosystems are extremely sensitive to nitrogen growth,which leads to water quality degradation and ecosystem health decline.Nitrogen depositions,as one of the main sources of nitrogen in water,are expected to change under future climate change scenarios.However,it remains not clear how nitrogen deposition to lakes respond to future meteorological conditions.In this study,a source-oriented version of Community Multiscale Air Quality(CMAQ)Model was used to estimate nitrogen deposition to 263 lakes in 2013 and under three RCP scenarios(4.5,6.0 and 8.5)in 2046.Annual total deposition of 58.2 Gg nitrogen was predicted for all lakes,with 23.3 Gg N by wet deposition and 34.9 Gg N by dry deposition.Nitrate and ammonium in aerosol phase are the major forms of wet deposition,while NH3 and HNO_(3)in gas phase are the major forms of dry deposition.Agriculture emissions contribute to 57%of wet deposition and 44%of dry deposition.Under future meteorological conditions,wet deposition is predicted to increase by 5.5%to 16.4%,while dry deposition would decrease by 0.3%to 13.0%.Changes in wind speed,temperature,relative humidity(RH),and precipitation rates are correlated with dry and wet deposition changes.The predicted changes in deposition to lakes driven by meteorological changes can lead to significant changes in aquatic chemistry and ecosystem functions.Apart from future emission scenarios,different climate scenarios should be considered in future ecosystem health evaluation in response to nitrogen deposition.
基金an extensive research project sponsored by the Company Ferrovial S.A.(Spain)conducted by the Geotechnical Group at the School of Civil Engineering,the University of Cantabria(Spain)
文摘This paper aims to study the shear interaction mechanism of one of the critical geosynthetic interfaces,the geotextile/geomembrane, typically used for lined containment facilities such as landfills. A largedirect shear machine is used to carry out 90 geosynthetic interface tests. The test results show a strainsoftening behavior with a very small dilatancy （〈0.5 mm） and nonlinear failure envelopes at a normalstress range of 25e450 kPa. The influences of the micro-level structure of these geosynthetics on themacro-level interface shear behavior are discussed in detail. This study has generated several practicalrecommendations to help professionals to choose what materials are more adequate. From the threegeotextiles tested, the thermally bonded monofilament exhibits the best interface shear strength underhigh normal stress. For low normal stress, however, needle-punched monofilaments are recommended.For the regular textured geomembranes tested, the space between the asperities is an important factor.The closer these asperities are, the better the result achieves. For the irregular textured geomembranestested, the nonwoven geotextiles made of monofilaments produce the largest interface shear strength.
基金the China Aviation Science Foundation (03D12004)
文摘The advanced missile uses blended control of nero-fin and reaction-jet to improve missile maneuverability. The blended control design, which is multi-inputs and multi-outputs （MIMO）, severe nonlinear, and model uncertain, is much more complex than conventional nero-fin control. A novel nonlinear backstepping control approach is proposed to design the blended autopilot. Missile model is reformed to a new one by state reconstruction technique so that it is easy to be handled by the backstepping method. Then a Lyapunov function is chosen to avoid oscillation caused in normal backstepping way when control parameters are mismatched. In distribution of both inputs, optimal energy logic is proposed. In addition, a fuzzy cerebellar model articulation controller （FCMAC） neural network is used to guarantee controller robustness to uncertainties. Finally, simulation results demonstrate the efficiency and advantages of the proposed method.
基金supported by the National Key Research and Development Program of China (2017YFD0101004)the Science and Technology Service Network Initiative of Chinese Academy of Sciences (KFJ-STS-ZDTP-024)
文摘Stripe rust and powdery mildew are both devastating diseases for durum and common wheat.Pyramiding of genes conferring resistance to one or more diseases in a single cultivar is an important breeding approach to provide broader spectra of resistances in wheat improvement. A new powdery mildew resistance gene originating from wild emmer(Triticum turgidum var.dicoccoides) backcrossed into common wheat(T. aestivum) line WE35 was identified. It conferred an intermediate level of resistance to Blumeria graminis f. sp. tritici isolate E09 at the seedling stage and a high level of resistance at the adult plant stage. Genetic analysis showed that the powdery mildew resistance in WE35 was controlled by a dominant gene designated Pm64. Bulked segregant analysis(BSA) and molecular mapping indicated that Pm64 was located in chromosome bin 2 BL4-0.50–0.89. Polymorphic markers were developed from the corresponding genomic regions of Chinese Spring wheat and wild emmer accession Zavitan to delimit Pm64 to a 0.55 cM genetic interval between markers WGGBH1364 and WGGBH612, corresponding to a 15 Mb genomic region on Chinese Spring and Zavitan 2 BL, respectively. The genetic linkage map of Pm64 is critical for fine mapping and cloning. Pm64 was completely linked in repulsion with stripe rust resistance gene Yr5. Analysis of a larger segregating population might identify a recombinant line with both genes as a valuable resource in breeding for resistance to powdery mildew and stripe rust.
基金funding support,which is Aerospace Science Foundation(NO.2017ZC12008)。
文摘The airborne missile launch mechanism often subjects to significant deformations induced by the large ejection force during high-speed actuations in missile ejection process,leading to a substantial deviation of separation parameters from designed values that threats safety of the carrier.This study proposes a novel variable topology design for launch mechanism,achieved via a Prsmatic-Revolute-Revolute pair(PR-R)motion formed by the structural gap with a specific direction.It enables launch mechanism variability during missile ejection process and optimizes the ejection force given by the front and back ejection arms,and greatly optimizes the separation parameters during missile ejection.The kinetics simulation analysis is conducted under working conditions of the original ejection mechanism and the novel mechanism with variable topology design,respectively.The results show that the novel variable topology design is more befitting for the launch process in terms of system safety and controllability,effectively improving the separation posture,restraining the flexible effect of the mechanism,and fulfilling the effectiveness of the design value of multi-rigid body.
基金National Natural Science Foundation of China(Nos.51803190,11432003,11572290)National Key Research and Development Program of China(No.2016YFB0101602)+2 种基金China Postdoctoral Science Foundation(Nos.2018M642779,2019M652573,2019T120643)International Postdoctoral Exchange Fellowship Program,University Key Research Project of Henan Province(No.18A430031)Guangdong Province Pearl River Scholar Funded Scheme(2016)for financial support。
文摘Polylactic acid(PLA) is one of the most suitable candidates for environmental pollution treatment because of its biodegradability which will not cause secondary pollution to the environment after application.However,there is still a lack of a green and facile way to prepare PLA oil-water separation materials.In this work,a water-assisted thermally induced phase separation method for the preparation of superhydrophobic PLA oil-water separation material with honeycomb-like structures is reported.The PLA material shows great ability in application and could adsorb 27.3 times oil to its own weight.In addition,it could also be applicated as a filter with excellent efficiency(50.9 m^3 m^(-2) h^(-1)).
基金financially supported by the Beijing Dairy Industry Innovation TeamFeed Quality and Safety Control Innovation Team of Chinese Academy of Agricultural Sciences
文摘The detection of chemical contaminants is critical to ensure dairy safety. These contaminants include veterinary medicines, antibiotics, pesticides, heavy metals, mycotoxins, and persistent organic pollutants （POPs）. Immunoassays have recently been used to detect contaminants in milk because of their simple operation, high speed, and low cost. This article describes the latest developments in the most important component of immunoassays--antibodies, and then reviews the four major substrates used for immunoassays （i.e., microplates, membranes, gels, and chips） as well as their use in the detection of milk contaminants. The paper concludes with prospects for further aDDlications of these immunoassavs.
基金supported by the National Natural Science Foundation of China(No.61803307,62111530051)Aeronautical Science Foundation of China(No.201901053004)+2 种基金Natural Science Basic Research Plan in Shaanxi Province of China(No.2020JQ-209)China Postdoctoral Science Foundation(No.2020M683565)the Fundamental Research Funds for the Central Universities(No.3102020ZDHKY05).
文摘This paper investigates the robust formation control for missiles with obstacle avoidance.A sliding mode surface that is asymptotically stable is firstly presented by the collision avoidance potential function and hyperbolic tangent function.Based on the sliding mode surface,a robust formation controller with obstacle avoidance is designed for missiles.To improve the convergence rate,a finite-time controller which can deal with the formation control for missiles is given using an improved sliding mode surface.Finally,the effectiveness of the designed controllers for missiles is demonstrated by the Lyapunov theory and simulation results.
基金supported by the National GMO New Variety Breeding Program of China(2015ZX08013-003)
文摘Adult Chrysoperla sinica Tjeder is a common pollen feeder in maize fields. They are thus directly exposed to insecticidal proteins by consumption of genetically engineered maize pollen containing Bacillus thuringiensis(Bt) proteins. Here we assessed the potential effects of Cry1 Ab/2 Aj-or Cry1 Ac-containing Bt maize pollen on the fitness of adult C. sinica via a dietary-exposure assay under laboratory conditions. Survival, pre-oviposition, fecundity and adult dry weight did not differ between adult C. sinica consuming Bt or the corresponding non-Bt maize pollen. The stability of the Cry protein in the food sources and uptake of the Cry protein by adult C. sinica during the feeding experiment were confirmed by ELISA. These results demonstrate that adult C. sinica are not affected by the consumption of Cry1 Ab/2 Aj-or Cry1 Ac-containing maize pollen, suggesting that production of Bt maize expressing cry1 Ab/2 Aj or cry1 Ac genes will pose a negligible risk to adult C. sinica.
基金the Nuclear Backend Management Department at Taiwan Power Company for financially supporting this research
文摘The characteristics of diffusion are essential to the transport of radionuclides through buffer/backfill materials, such as bentonite, which are commonly found in waste repositories. This study used through-diffusion techniques to investigate the diffusion behavior of HTO and ^(99)TcO_4^- on GMZ bentonite of various densities. Diffusion rates were calculated by measuring the diffusion coefficients(De, Da), plotting breakthrough curves and interpreting experiment data. The apparent and effective diffusion coefficients of HTO ranged from(1.68 ± 0.40) 9 × 10^(-11) to(2.80 ± 0.62) 9 × 10^(-11) m^2/s and from(4.61 ±1.28) 9 × 10^(-12) to (16.2 ± 2.50) 9 × 10^(-12) m^2/s, respectively.The apparent and effective diffusion coefficients of^(99)TcO_4^-ranged from(5.26 ± 0.16) 9 × 10^-12to(7.78 ± 0.43) 9× 10^-12m^2/s and from(1.49 ± 0.002) 9 × 10^(-12) to(4.16 ±0.07) 9 × 10^(-12) m^2/s, respectively. The distribution coefficients of HTO and^(99)TcO_4^-ranged from(0.70 ± 0.12) 9× 10^(-2) to(1.36 ± 0.53) 9 × 10^(-2) mL/g and from(1.12 ±0.06) 9 × 10^(-2) to(5.79 ± 2.22) 9 × 10^(-2) mL/g, respectively.The Deand Kdvalues were shown to decrease with an increase in the bulk dry density of compacted bentonite. Our results show that HTO and ^(99)Tc could be considered nonsorbent radionuclides. The data obtained in this studyprovide a valuable reference for the safety assessment of waste repositories.
基金supported by the Young Elite Scientists Sponsorship Program by the China Association for Science and Technology(No.2016QNRC001)the Science and Technology Commission of Shanghai Municipality,China(No.19DZ1100300)。
文摘This study focuses on the thermo-mechanical properties of Carbon Fibre/Polyimide Composite(CFPC)attaching collars under transient heating.The CFPC attaching collars were fabricated by a high-temperature resin transfer moulding process,and their thermo-mechanical properties under the conditions of simultaneous transient heating and bending load were investigated.The results show that the attaching collar tends to fail at 118% of the limit load.The failure mode includes the fracture of the connecting screws,local extrusion damage of the hole edges,and slight ablation damage at the outer plies.And there is no observable residual deformation in the composite attaching collar.Furthermore,considering that the material properties vary with temperature,a progressive damage model based on the sequential thermo-mechanical coupling method was established to study the failure mechanism of the attaching collar.Finally,the damage factor of the CFPC was calculated to assess the safety status of the attaching collar.The results show that the primary damage modes of the composite attaching collar are intralaminar failure,which mainly occurs at the heat insulation layer and the hole edges,and these slightly affect the structural bearing capacity.A good correlation between the experiment and FEA is obtained.The test methods and analysis models proposed contribute to the safety assessment of composite structures under transient heating.
基金The authors thank the financial support of this study received by the National Natural Science Foundation of China(21802173,21822509,and U1810110)Science and Technology Planning Project of Guangdong Province(2018A050506028)Youth Innovation Talents Project of Guangdong Universities(natural science)(2019KQNCX098).
文摘The ever-growing market of wearable electronic devices has greatly stimulated the rapid development of flexible Zn-ion batteries(ZIBs).Manganese oxides are one of the most commonly used hosts for zinc ion accommodation and thus receive particular research interest for high-performance flexible ZIB constructions.In this review,a comprehensive summary of the recent development of flexible ZIBs with manganese oxides as cathode materials is presented.Apart from the brief introduction of flexible electronic devices and ZIBs,the charge storage mechanisms and crystal structures of various manganese oxides are summarized.Modifications of the cathode materials in terms of morphology,conductivity,structures,and flexibilities are illustrated in detail,together with the demonstration of structure-performance relationships and applications in flexible ZIBs.Finally,limitations to be overcome are indicated and the future work directions are proposed.
