[Objectives]This study was conducted to observe the therapeutic effect of Jipei Dilong Ointment on rats with acute soft tissue injury caused by heavy objects and to explore its action mechanism.[Methods]Thirty six rat...[Objectives]This study was conducted to observe the therapeutic effect of Jipei Dilong Ointment on rats with acute soft tissue injury caused by heavy objects and to explore its action mechanism.[Methods]Thirty six rats were randomly divided into six groups(control group,model group,high-dose Jipei Dilong Ointment group(JP-H),medium-dose Jipei Dilong Ointment group(JP-M),low-dose Jipei Dilong Ointment group(JP-L)and diclofenac group).Except for the Control group,other groups were subjected to modeling of acute soft tissue injury by the weight impact method.All administration was performed once a day for nine consecutive days.The local appearance score and activity disorder score were determined after soft tissue injury in rats.HE staining was used to detect the pathological changes of injured soft tissues in rats.RT-PCR was used to detect the relative mRNA expressions of Bax,Bcl-2,MMP-9 and TIMP-1 in injured soft tissues of rats.Western Blot was used to detect the protein expressions of MMP-9,TIMP-1,TLR4,MyD88 and NF-κB p65 in injured soft tissues of rats.Results were statistically analyzed.[Results]Compared with the model group,Jipei Dilong Ointment could significantly improve the appearance symptoms such as swelling and ecchymosis in the injured area and the movement function of the affected limb(P<0.05).It could also improve the infiltration of inflammatory cells and widening of the intermuscular space caused by injury.Among them,the JP-H group and the diclofenac group had more significant curative effects.After 9 d of administration,each administration group could significantly up-regulate the ratio of Bcl-2/Bax mRNA expression level(P<0.05 or P<0.01),and the ratio of MMP-9/TIMP-1 mRNA expression level showed a downward trend(P>0.05).The expression level of NF-κB p65 protein in each administration group was significantly decreased(P<0.01).The protein expression levels of TLR4 and MyD88 and the ratio of MMP-9/TIMP-1 protein expression level in each administration group decreased to varying degrees.Among them,the JP-H group and diclofenac group significantly decreased(P<0.05).[Conclusions]Jipei Dilong Ointment has the functions of relieving pain,swelling and inflammation.It could improve the local appearance,functional activity and tissue morphology of affected limbs in rats,and has a therapeutic effect on acute soft tissue injury in rats.Its mechanism of action might be related to the inhibition of TLR4/MyD88/NF-κB p65 signaling pathway and the regulation of Bcl-2/Bax and MMP-9/TIMP-1 balance.展开更多
[Objectives]To explore the protective effect and molecular mechanism of Shui People s Classic Prescription Jipei Dilong Ointment on knee osteoarthritis in rats.[Methods]72 SPF male SD rats were divided into control gr...[Objectives]To explore the protective effect and molecular mechanism of Shui People s Classic Prescription Jipei Dilong Ointment on knee osteoarthritis in rats.[Methods]72 SPF male SD rats were divided into control group,model group,Jipei Dilong Ointment high,medium and low dose groups,and positive drug Diclofenac group,with 12 rats in each group.Except the control group,all other groups were injected with 0.2 mL of 2%papain and 0.3%L-cysteine mixture into knee joint cavity to establish osteoarthritis model,while the control group was injected with the same amount of normal saline.The Lequesne MG score was used to determine the success of the model.After successful modeling,external administration was given for 4 weeks.The histopathological changes in articular cartilage and synovium were observed by HE staining;the levels of TNF-α,IL-1βand COX-2 in serum were detected by ELISA,and the relative expression of MMP-9 and TIMP-1 mRNA in cartilage was detected by qRT-PCR;the relative expression of MMP-9,TIMP-1,TLR4,MyD88 and NF-κB in rat cartilage was detected by Western-blot.[Results]Compared with the model group,Jipei Dilong Ointment could significantly reduce the Lequesne MG score and Mankin s score of arthritic rats(P<0.01);significantly improve the pathological changes in articular cartilage and synovium,reduce tissue edema,necrosis,inflammatory cell infiltration and fibrous tissue proliferation;reduce the expression of MMP-9 mRNA(P<0.01)in different degrees and increase the expression of TIMP-1 mRNA(P<0.01);reduce the relative expression of MMP-9,TLR4,MyD88 and NF-κB protein in different degrees(P<0.01),and significantly increase the relative expression of TIMP-1 protein in cartilage(P<0.01).[Conclusions]Jipei Dilong Ointment can improve the joint injury of osteoarthritis rats,and the mechanism may be related to the regulation of TLR4/MyD88/NF-κB signaling pathway and the ratio of MMP-9/TIMP-1.展开更多
To quantitatively analyze main figure,field,agency and level of sponge city research in China,and clear research focus and hot spot in each year,by using the Full Text Database of Chinese Sci-tech Periodicals and othe...To quantitatively analyze main figure,field,agency and level of sponge city research in China,and clear research focus and hot spot in each year,by using the Full Text Database of Chinese Sci-tech Periodicals and other retrieval tools,the statistics and analysis of 3152 research literatures on sponge city published in domestic academic journals of 2004-2016 are conducted based on bibliometrics. It is found that since the concept of " sponge city" was firstly proposed in 2012,development research of sponge city involves 40 subject fields and is mainly published in 32 kinds of journals,which is dominated by natural science research( 1427 literatures). Researchers are mainly from each college and university,some design institutes and Chinese Academy of Sciences. The research could play certain guidance significance for further research and construction of ecological city construction in China.展开更多
Through exploring the material and nonmaterial cultural resources in leisure agriculture of Sani People in Shilin of Yunnan Province,this paper introduced festivals,marriage,traditional clothing,and food culture of Sa...Through exploring the material and nonmaterial cultural resources in leisure agriculture of Sani People in Shilin of Yunnan Province,this paper introduced festivals,marriage,traditional clothing,and food culture of Sani People,and present the long history and brilliant culture of Sani People. These culture resources could be used to expand the cultural aspects of leisure agriculture,to solve the problems of low participation and less distinct characteristics. This study can provide a reference for building the high-end leisure agriculture with distinct characteristics of Yunnan Province,to form a new growth point for regional growth.展开更多
In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by th...In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by the senders if and only if the two sides meet their defined certain policies simultaneously.Specifically,we first formalize the definition and security models of fuzzy matching data sharing in cloud-edge environments.Then,we construct a concrete instantiation by pairing-based cryptosystem and the privacy-preserving set intersection on attribute sets from both sides to construct a concurrent matching over the policies.If the matching succeeds,the data can be decrypted.Otherwise,nothing will be revealed.In addition,FADS allows users to dynamically specify the policy for each time,which is an urgent demand in practice.A thorough security analysis demonstrates that FADS is of provable security under indistinguishable chosen ciphertext attack(IND-CCA)in random oracle model against probabilistic polynomial-time(PPT)adversary,and the desirable security properties of privacy and authenticity are achieved.Extensive experiments provide evidence that FADS is with acceptable efficiency.展开更多
Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular c...Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and combustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.展开更多
To achieve hydrodynamic design excellence in Autonomous Underwater Vehicles(AUVs)largely depends on the accurate prediction of lift and drag forces.The study presents Computational Fluid Dynamics(CFD)-based lift and d...To achieve hydrodynamic design excellence in Autonomous Underwater Vehicles(AUVs)largely depends on the accurate prediction of lift and drag forces.The study presents Computational Fluid Dynamics(CFD)-based lift and drag estimations of a novel torpedo-shaped flight-style AUV with bow-wings.The horizontal bow-wings are provided to accommodate the electromagnetic arrays used to perform the cable detection and tracking operations near the seabed.The hydrodynamic performance of the AUV due to addition of these horizontal bow-wings is required to be investigated,particularly at the initial design stage.Hence,CFD techniques are employed to compute the lift and drag forces observed by the flight-style AUV,maneuvering underwater at different angles of attack and varying speeds.The Reynolds-Averaged Navier-Stokes Equations(RANSE)closure is achieved by employing the modified k-ϵ model and Two-Scale Wall Function(2-SWF)approach is used for boundary layer treatment.Further,the study also highlights the unique mesh refinement and solution-adaptive meshing techniques to perform the CFD simulations in Solidworks Flow Simulation(SWFS)environment.The drag polar curve for flight-style AUV with and without bow-wings is generated using the computed lift and drag coefficients.The curve provided essential insights for achieving hydrodynamically efficient and optimized AUV design.From the drag polar curve,it is revealed that due to horizontal bow-wings,the flight-style AUV is capable to generate higher lift with less drag and thus,it gives better lift-to-drag ratio compared to the AUV without bow-wings.Moreover,simulated results of axial drag observed by the AUV have also been compared with free-running experimental results and are found in good agreement.展开更多
Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction betwee...Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction between these two processes is less understood so far.This study investigated the bioaccumulation kinetics of PAHs and metabolic enzyme activities,including total cytochrome P450(CYPs)and total superoxide dismutase(T-SOD),in zebrafish.Mature zebrafish were exposed to the mixture of phenanthrene and anthracene under constant concentration maintained by passive dosing systems for 16 days.The results showed that PAH concentrations in zebrafish experienced a peak value after exposure for 1.5 days,and then decreased gradually.The bioaccumulation equilibrium was achieved after exposure for 12 days.Both of the uptake rate constants(k_u)and the elimination rate constants(k_e)decreased after the peak value.The variation of PAH concentrations and metabolic enzyme activities in zebrafish had an interactive relationship.The activities of CYPs and T-SOD increased initially with the increase of PAH concentrations,but decreased to the lowest state when PAH concentrations reached the peak value.When the bioaccumulation equilibrium of PAHs was achieved,CYPs and T-SOD activities also reached the steady state.In general,CYPs and T-SOD activities were activated after exposure to PAHs.The decrease of PAH concentrations in zebrafish after the peak value may be attributed to the great drop of k_uand the variation of CYPs activities.This study suggests that an interactive relationship exists between bioaccumulation kinetics of PAHs and metabolic enzyme activities in aquatic organisms.展开更多
The presence of lightning impulses(LIs)on the DC waveform can seriously influence the insulation performance of a GIL system.The waveshape can be a superposition of the DC and impulse waveform.In this study,the behavi...The presence of lightning impulses(LIs)on the DC waveform can seriously influence the insulation performance of a GIL system.The waveshape can be a superposition of the DC and impulse waveform.In this study,the behaviour of partial discharge(PD)on an epoxy surface is investigated under DC and LI superimposed voltage in SF6.The lightning impulses with different polarities are superimposed on the epoxy surface under both positive and negative DC voltages,respectively.Positive lightning impulses are superimposed on a negative DC voltage with a 90%of the partial discharge inception voltage(PDIV)magnitude.The number and amplitude of the PDs are used to evaluate the insulation performance.The experimental results show that the LI with a different polarity applied to DC can excite the PDs on the epoxy surface.The excitation effect of positive LI superimposed on negative DC is more significant.According to the impulse amplitude and PD characteristics,the influence of superimposed LI on PD excitation can be divided into three stages.As the superimposed LI increases,the amplitude of the excited PD increases gradually,while the PD number first increases and then decreases.This study is expected to provide reference for manufacture and protection of power equipment.展开更多
CO_(2)is a representative prototype model in energy and environmental fields.Many factors for CO_(2)capture and activation have been investigated extensively but the research on the influence of thermal conductivity i...CO_(2)is a representative prototype model in energy and environmental fields.Many factors for CO_(2)capture and activation have been investigated extensively but the research on the influence of thermal conductivity is still absence.We herein have calculated many properties,including dipole moment,electric structure,and adsorption energies,on Pt doped graphene and 2D BC_(3)N_(2)substrates and served the thermal conductivity as the bridge.Our results have demonstrated that the lower (higher) thermal conductivity for 2D BC_(3)N_(2)(graphene) corresponds to larger (lower) dipole moment,which is beneficial for CO_(2)activation (capture) process.Our research have not only revealed the dominant role of heat conductivity for CO_(2)capture and activation,but also paved the way for further catalyst design of various areas.展开更多
Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodi...Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodium metal batteries.Here,we overturn this conclusion by incorporating fluoroethylene carbonate(FEC)as cosolvent that renders a Na plating/stripping fficiency of>95%with conventional NaPF。salt at a regular concentration(1.0M).The peculiar role of FEC is firstly.unraveled via its involvement into the solvation structure,where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term.Specifially,by incorporating an average number of 1.2 FEC molecules into the primary Na*solvation sheath,lowest unoccupied molecular orbital(LUMO)levels of such Nat-FEC solvates undergo further decrease,with spin electrons residing either on the O=C 0(O)moiety of FEC or sharing between Na*and its C=:O bond,which ensures a prior FEC decomposition in passivating the Na surface against other carbonate molecules.Further,by adopting cryogenic tranmission electron microscopy(cryo-TEM),we found that the Na filaments grow into substantially larger diameter from-400nm to>1 pum with addition of FEC upon the threshold value.A.highly crstalline and much thiner(-40 nm)slid-electrolyte interphase(SED)is consequently observed to uniformly wrap the Na surface,in contrast to the severely corroded Na as retrieved from the blank electrolyte.The potence of FEC is further demonstrated in a series of"corrosive solvents"such as ethy!l acetate(EA)。trimethyl phosphate(TMP),and actonitrile(AN)enabling highly reversible SMAs in the otherwise unusable solvent systems.展开更多
Transition radiation(TR) induced by electron–matter interaction usually demands vast accelerating voltages, and the radiation angle cannot be controlled. Here we present a mechanism of direction controllable inverse ...Transition radiation(TR) induced by electron–matter interaction usually demands vast accelerating voltages, and the radiation angle cannot be controlled. Here we present a mechanism of direction controllable inverse transition radiation(DCITR) in a graphene-dielectric stack excited by low-velocity electrons. The revealed mechanism shows that the induced hyperbolic-like spatial dispersion and the superposition of the individual bulk graphene plasmons(GPs) modes make the fields, which are supposed to be confined on the surface, radiate in the stack along a special radiation angle normal to the Poynting vector. By adjusting the chemical potential of the graphene sheets, the radiation angle can be controlled. And owing to the excitation of bulk GPs, only hundreds of volts for the accelerating voltage are required and the field intensity is dramatically enhanced compared with that of the normal TR. Furthermore, the presented mechanism can also be applied to the hyperbolic stack based on semiconductors in the infrared region as well as noble metals in the visible and ultraviolet region.Accordingly, the presented mechanism of DCITR is of great significance in particle detection, radiation emission,and so on.展开更多
Solar greenhouse is a typical greenhouse without any additional heating system,which has developed rapidly in Northern China.However,due to the construction quality,management methods,especially the long-term use and ...Solar greenhouse is a typical greenhouse without any additional heating system,which has developed rapidly in Northern China.However,due to the construction quality,management methods,especially the long-term use and other factors,there are usually different degrees of thermodynamic disfigurements in the envelop enclosure of solar greenhouse.The purpose of this study was to investigate the influences of thermodynamic disfigurement on the temperature distribution and convective heat transfer of solar greenhouse.In this study,the east and west compartments of a typical solar greenhouse which is located in Yangling,China(108°4′E,34°16′N)were tested.The air temperature of each compartment was collected using temperature recorders,and the thermal infrared images of different compartment envelopes were obtained by a thermal infrared imager on a typical cloudy day.Convective heat transfer coefficients and heat flux densities of different compartment envelopes in the solar greenhouse were calculated.The results showed that the temperature difference can be displayed in the thermal infrared images of compartment envelopes,the surface temperature of the front roof was the lowest,followed by the back roof,the wall surface temperature was the highest.The minimum average surface temperature of the front roof in the eastern compartment was only 3.8℃,which was 6.8℃ and 9.2℃ lower than the average surface temperature of the back roof and back wall,respectively.The surface average temperature of thermodynamic disfigurements located at the bottom of the south side in the front roof of the eastern compartment,whose area accounted for 16.5%of the total front roof in the eastern compartment,was only 5.4℃.Compared with non-thermodynamic disfigurement,the average convective heat transfer coefficient and heat flux density of thermodynamic disfigurements in the front roof of the eastern compartment were increased by 20.3%and 110.3%,respectively.The average air temperature in the eastern compartment was 3.5℃ lower than the average air temperature in the western compartment of the solar greenhouse.Construction of brick wall at the bottom of the south side of the front roof in the solar greenhouse helped to increase the inner surface temperature of the front roof,with an average temperature rise of 6.2℃,and reduce the area of thermodynamic disfigurement,which only accounted for 2.6%of the total front roof in the western compartment.The average surface temperature of thermodynamic disfigurements mainly caused by the entry and exit door in the wall of the eastern compartment was only 9.8℃,which was lower 3.2℃ than the average temperature of non-thermodynamic disfigurement of the wall.Thermodynamic disfigurement helped to increase heat loss.The weighted average proportion of thermodynamic disfigurement in the western compartment was 2.1%,while that of thermodynamic disfigurement in the eastern compartment was 10.7%.The thermal insulation performance of the western compartment envelope in the solar greenhouse was better than that of the eastern compartment envelope.展开更多
基金Supported by National Key R&D Plan(2019YFC1712500)Guizhou Provincial Science and Technology Planning Project(QKHHBZ[2020]3003)On-campus Project of Guizhou University of Traditional Chinese Medicine(2018YFC170810520).
文摘[Objectives]This study was conducted to observe the therapeutic effect of Jipei Dilong Ointment on rats with acute soft tissue injury caused by heavy objects and to explore its action mechanism.[Methods]Thirty six rats were randomly divided into six groups(control group,model group,high-dose Jipei Dilong Ointment group(JP-H),medium-dose Jipei Dilong Ointment group(JP-M),low-dose Jipei Dilong Ointment group(JP-L)and diclofenac group).Except for the Control group,other groups were subjected to modeling of acute soft tissue injury by the weight impact method.All administration was performed once a day for nine consecutive days.The local appearance score and activity disorder score were determined after soft tissue injury in rats.HE staining was used to detect the pathological changes of injured soft tissues in rats.RT-PCR was used to detect the relative mRNA expressions of Bax,Bcl-2,MMP-9 and TIMP-1 in injured soft tissues of rats.Western Blot was used to detect the protein expressions of MMP-9,TIMP-1,TLR4,MyD88 and NF-κB p65 in injured soft tissues of rats.Results were statistically analyzed.[Results]Compared with the model group,Jipei Dilong Ointment could significantly improve the appearance symptoms such as swelling and ecchymosis in the injured area and the movement function of the affected limb(P<0.05).It could also improve the infiltration of inflammatory cells and widening of the intermuscular space caused by injury.Among them,the JP-H group and the diclofenac group had more significant curative effects.After 9 d of administration,each administration group could significantly up-regulate the ratio of Bcl-2/Bax mRNA expression level(P<0.05 or P<0.01),and the ratio of MMP-9/TIMP-1 mRNA expression level showed a downward trend(P>0.05).The expression level of NF-κB p65 protein in each administration group was significantly decreased(P<0.01).The protein expression levels of TLR4 and MyD88 and the ratio of MMP-9/TIMP-1 protein expression level in each administration group decreased to varying degrees.Among them,the JP-H group and diclofenac group significantly decreased(P<0.05).[Conclusions]Jipei Dilong Ointment has the functions of relieving pain,swelling and inflammation.It could improve the local appearance,functional activity and tissue morphology of affected limbs in rats,and has a therapeutic effect on acute soft tissue injury in rats.Its mechanism of action might be related to the inhibition of TLR4/MyD88/NF-κB p65 signaling pathway and the regulation of Bcl-2/Bax and MMP-9/TIMP-1 balance.
基金Supported by National Key R&D Program(2019YFC1712500)Science and Technology Program of Guizhou Province([2020]3003)Project of Guizhou University of Traditional Chinese Medicine(2018YFC170810520).
文摘[Objectives]To explore the protective effect and molecular mechanism of Shui People s Classic Prescription Jipei Dilong Ointment on knee osteoarthritis in rats.[Methods]72 SPF male SD rats were divided into control group,model group,Jipei Dilong Ointment high,medium and low dose groups,and positive drug Diclofenac group,with 12 rats in each group.Except the control group,all other groups were injected with 0.2 mL of 2%papain and 0.3%L-cysteine mixture into knee joint cavity to establish osteoarthritis model,while the control group was injected with the same amount of normal saline.The Lequesne MG score was used to determine the success of the model.After successful modeling,external administration was given for 4 weeks.The histopathological changes in articular cartilage and synovium were observed by HE staining;the levels of TNF-α,IL-1βand COX-2 in serum were detected by ELISA,and the relative expression of MMP-9 and TIMP-1 mRNA in cartilage was detected by qRT-PCR;the relative expression of MMP-9,TIMP-1,TLR4,MyD88 and NF-κB in rat cartilage was detected by Western-blot.[Results]Compared with the model group,Jipei Dilong Ointment could significantly reduce the Lequesne MG score and Mankin s score of arthritic rats(P<0.01);significantly improve the pathological changes in articular cartilage and synovium,reduce tissue edema,necrosis,inflammatory cell infiltration and fibrous tissue proliferation;reduce the expression of MMP-9 mRNA(P<0.01)in different degrees and increase the expression of TIMP-1 mRNA(P<0.01);reduce the relative expression of MMP-9,TLR4,MyD88 and NF-κB protein in different degrees(P<0.01),and significantly increase the relative expression of TIMP-1 protein in cartilage(P<0.01).[Conclusions]Jipei Dilong Ointment can improve the joint injury of osteoarthritis rats,and the mechanism may be related to the regulation of TLR4/MyD88/NF-κB signaling pathway and the ratio of MMP-9/TIMP-1.
基金Supported by Science Research Fund of Yunnan Provincial Education Department(2017ZZX090)School-level Key Project of Kunming University(XJZD1602)"Study on Key Technology of Ecological Planting Mode of Balcony Vegetables"of Provincial-level"Quality Project"of Kunming University-Innovation and Entrepreneurship Training Program for College Students
文摘To quantitatively analyze main figure,field,agency and level of sponge city research in China,and clear research focus and hot spot in each year,by using the Full Text Database of Chinese Sci-tech Periodicals and other retrieval tools,the statistics and analysis of 3152 research literatures on sponge city published in domestic academic journals of 2004-2016 are conducted based on bibliometrics. It is found that since the concept of " sponge city" was firstly proposed in 2012,development research of sponge city involves 40 subject fields and is mainly published in 32 kinds of journals,which is dominated by natural science research( 1427 literatures). Researchers are mainly from each college and university,some design institutes and Chinese Academy of Sciences. The research could play certain guidance significance for further research and construction of ecological city construction in China.
基金Supported by Science and Technology Project Research of Kunming University "Study on Yunnan Leisure Agriculture Cultural Origin"(XJL13021)Yunnan Province Urban Leisure Agriculture Engineering Technology Research Center Project "Study on Family Leisure Farm Circular Agriculture Development Model"(XXNY1410)+2 种基金Construction Project of Key Superior and Characteristic Disciplines(Ecology) in Colleges and Universities of Yunnan ProvinceScientific Research Foundation of Yunnan Provincial Department of Education "Study on Ecological Reconstruction of Old City Based on Low Impact Development Target"(2017ZZX090)Science and Technology Project Research of Kunming University "Study on LID System Theory Construction of Sponge City Landscape Corridor"(XJZD1602)
文摘Through exploring the material and nonmaterial cultural resources in leisure agriculture of Sani People in Shilin of Yunnan Province,this paper introduced festivals,marriage,traditional clothing,and food culture of Sani People,and present the long history and brilliant culture of Sani People. These culture resources could be used to expand the cultural aspects of leisure agriculture,to solve the problems of low participation and less distinct characteristics. This study can provide a reference for building the high-end leisure agriculture with distinct characteristics of Yunnan Province,to form a new growth point for regional growth.
基金supported by the China Postdoctoral Science Foundation (Grant Nos. 2021TQ0042, 2021M700435, 2021TQ0041)the National Natural Science Foundation of China (Grant No. 62102027)the Shandong Provincial Key Research and Development Program (2021CXGC010106)
文摘In this paper,we propose a novel fuzzy matching data sharing scheme named FADS for cloudedge communications.FADS allows users to specify their access policies,and enables receivers to obtain the data transmitted by the senders if and only if the two sides meet their defined certain policies simultaneously.Specifically,we first formalize the definition and security models of fuzzy matching data sharing in cloud-edge environments.Then,we construct a concrete instantiation by pairing-based cryptosystem and the privacy-preserving set intersection on attribute sets from both sides to construct a concurrent matching over the policies.If the matching succeeds,the data can be decrypted.Otherwise,nothing will be revealed.In addition,FADS allows users to dynamically specify the policy for each time,which is an urgent demand in practice.A thorough security analysis demonstrates that FADS is of provable security under indistinguishable chosen ciphertext attack(IND-CCA)in random oracle model against probabilistic polynomial-time(PPT)adversary,and the desirable security properties of privacy and authenticity are achieved.Extensive experiments provide evidence that FADS is with acceptable efficiency.
基金the National Natural Science Foundation of China(Grant No.12072347)the Excellent Training Plan of the Institute of Mechanics,Chinese Academy of Sciences,and CNPC New Energy Key Project(Grant No.2021DJ4902).
基金supported by the National Natural Science Foundation of China(92143301 and 91843301)the National Key Research and Development Program of China(2020YFF01014504)the Chinese Academy Sciences Youth Innovation Promotion Association projects。
文摘Aerosol-bound organic radicals,including environmentally persistent free radicals(EPFRs),are key components that affect climate,air quality,and human health.While putative structures have been proposed,the molecular characteristics of EPFRs remain unknown.Here,we report a surrogate method to characterize EPFRs in real ambient samples using mass spectrometry.The method identifies chemically relevant oxygenated polycyclic aromatic hydrocarbons(OxPAH)that interconvert with oxygen-centered EPFR(OC-EPFR).We found OxPAH compounds most relevant to OC-EPFRs are structurally rich and diverse quinones,whose diversity is strongly associated with OC-EPFR levels.Both atmospheric oxidation and combustion contributed to OC-EPFR formation.Redundancy analysis and photochemical aging model show pyrolytic sources generated more oxidized OC-EPFRs than photolytic sources.Our study reveals the detailed molecular characteristics of OC-EPFRs and shows that oxidation states can be used to identify the origins of OC-EPFRs,offering a way to track the development and evolution of aerosol particles in the environment.
基金supported in part by the National Natural Science Foundation of China(Grant Nos.52131101 and 52071153)in part by Hubei Natural Science Foundation for Innovation Groups(Grant No.2021CFA026).
文摘To achieve hydrodynamic design excellence in Autonomous Underwater Vehicles(AUVs)largely depends on the accurate prediction of lift and drag forces.The study presents Computational Fluid Dynamics(CFD)-based lift and drag estimations of a novel torpedo-shaped flight-style AUV with bow-wings.The horizontal bow-wings are provided to accommodate the electromagnetic arrays used to perform the cable detection and tracking operations near the seabed.The hydrodynamic performance of the AUV due to addition of these horizontal bow-wings is required to be investigated,particularly at the initial design stage.Hence,CFD techniques are employed to compute the lift and drag forces observed by the flight-style AUV,maneuvering underwater at different angles of attack and varying speeds.The Reynolds-Averaged Navier-Stokes Equations(RANSE)closure is achieved by employing the modified k-ϵ model and Two-Scale Wall Function(2-SWF)approach is used for boundary layer treatment.Further,the study also highlights the unique mesh refinement and solution-adaptive meshing techniques to perform the CFD simulations in Solidworks Flow Simulation(SWFS)environment.The drag polar curve for flight-style AUV with and without bow-wings is generated using the computed lift and drag coefficients.The curve provided essential insights for achieving hydrodynamically efficient and optimized AUV design.From the drag polar curve,it is revealed that due to horizontal bow-wings,the flight-style AUV is capable to generate higher lift with less drag and thus,it gives better lift-to-drag ratio compared to the AUV without bow-wings.Moreover,simulated results of axial drag observed by the AUV have also been compared with free-running experimental results and are found in good agreement.
基金supported by the National Science Foundation for Distinguished Young Scholars (No.51325902)the National Natural Science Foundation of China (No.91547207)the National Natural Science Foundation for Innovative Research Group (No.51421065)
文摘Many studies have investigated bioaccumulation and metabolism of polycyclic aromatic hydrocarbons(PAHs)in aquatic organisms.However,lack of studies investigated both processes simultaneously,and the interaction between these two processes is less understood so far.This study investigated the bioaccumulation kinetics of PAHs and metabolic enzyme activities,including total cytochrome P450(CYPs)and total superoxide dismutase(T-SOD),in zebrafish.Mature zebrafish were exposed to the mixture of phenanthrene and anthracene under constant concentration maintained by passive dosing systems for 16 days.The results showed that PAH concentrations in zebrafish experienced a peak value after exposure for 1.5 days,and then decreased gradually.The bioaccumulation equilibrium was achieved after exposure for 12 days.Both of the uptake rate constants(k_u)and the elimination rate constants(k_e)decreased after the peak value.The variation of PAH concentrations and metabolic enzyme activities in zebrafish had an interactive relationship.The activities of CYPs and T-SOD increased initially with the increase of PAH concentrations,but decreased to the lowest state when PAH concentrations reached the peak value.When the bioaccumulation equilibrium of PAHs was achieved,CYPs and T-SOD activities also reached the steady state.In general,CYPs and T-SOD activities were activated after exposure to PAHs.The decrease of PAH concentrations in zebrafish after the peak value may be attributed to the great drop of k_uand the variation of CYPs activities.This study suggests that an interactive relationship exists between bioaccumulation kinetics of PAHs and metabolic enzyme activities in aquatic organisms.
文摘The presence of lightning impulses(LIs)on the DC waveform can seriously influence the insulation performance of a GIL system.The waveshape can be a superposition of the DC and impulse waveform.In this study,the behaviour of partial discharge(PD)on an epoxy surface is investigated under DC and LI superimposed voltage in SF6.The lightning impulses with different polarities are superimposed on the epoxy surface under both positive and negative DC voltages,respectively.Positive lightning impulses are superimposed on a negative DC voltage with a 90%of the partial discharge inception voltage(PDIV)magnitude.The number and amplitude of the PDs are used to evaluate the insulation performance.The experimental results show that the LI with a different polarity applied to DC can excite the PDs on the epoxy surface.The excitation effect of positive LI superimposed on negative DC is more significant.According to the impulse amplitude and PD characteristics,the influence of superimposed LI on PD excitation can be divided into three stages.As the superimposed LI increases,the amplitude of the excited PD increases gradually,while the PD number first increases and then decreases.This study is expected to provide reference for manufacture and protection of power equipment.
基金funded by the Natural Science Foundation of China (Nos.21603109,52006130)the Henan Joint Fund of the National Natural Science Foundation of China (No.U1404216)+3 种基金China Postdoctoral Science Foundation (Nos.2020M670321,2021T140359)the Special Fund of Tianshui Normal University,China (No.CXJ2020-08)the Scientific Research Program Funded by Shaanxi Provincial Education Department (No.20JK0676)The Youth Innovation Team of Shaanxi Universities (No.21JP017)。
文摘CO_(2)is a representative prototype model in energy and environmental fields.Many factors for CO_(2)capture and activation have been investigated extensively but the research on the influence of thermal conductivity is still absence.We herein have calculated many properties,including dipole moment,electric structure,and adsorption energies,on Pt doped graphene and 2D BC_(3)N_(2)substrates and served the thermal conductivity as the bridge.Our results have demonstrated that the lower (higher) thermal conductivity for 2D BC_(3)N_(2)(graphene) corresponds to larger (lower) dipole moment,which is beneficial for CO_(2)activation (capture) process.Our research have not only revealed the dominant role of heat conductivity for CO_(2)capture and activation,but also paved the way for further catalyst design of various areas.
基金sponsored by the National Natural Science Foundation of China(NSFC Nos.21975186,51632001,and 22005334)supports from Natural Science Foundation of Beijing(grant No.Z200013).
文摘Sodium metal anodes(SMAs)sufer from extremely low reversibility(<20%)in carbonate based clectrolytes-this piece of knowledge gained from previous studics has ruled out the application of carbonate solvents for sodium metal batteries.Here,we overturn this conclusion by incorporating fluoroethylene carbonate(FEC)as cosolvent that renders a Na plating/stripping fficiency of>95%with conventional NaPF。salt at a regular concentration(1.0M).The peculiar role of FEC is firstly.unraveled via its involvement into the solvation structure,where a threshold FEC concentration with a coordination number>1.2 is needed in guaranteeing high Na reversibility over the long-term.Specifially,by incorporating an average number of 1.2 FEC molecules into the primary Na*solvation sheath,lowest unoccupied molecular orbital(LUMO)levels of such Nat-FEC solvates undergo further decrease,with spin electrons residing either on the O=C 0(O)moiety of FEC or sharing between Na*and its C=:O bond,which ensures a prior FEC decomposition in passivating the Na surface against other carbonate molecules.Further,by adopting cryogenic tranmission electron microscopy(cryo-TEM),we found that the Na filaments grow into substantially larger diameter from-400nm to>1 pum with addition of FEC upon the threshold value.A.highly crstalline and much thiner(-40 nm)slid-electrolyte interphase(SED)is consequently observed to uniformly wrap the Na surface,in contrast to the severely corroded Na as retrieved from the blank electrolyte.The potence of FEC is further demonstrated in a series of"corrosive solvents"such as ethy!l acetate(EA)。trimethyl phosphate(TMP),and actonitrile(AN)enabling highly reversible SMAs in the otherwise unusable solvent systems.
基金National Key Research and Development Program of China(2017YFA0701000,2018YFF01013001)National Natural Science Foundation of China(NSFC)(61505022,61701084).
文摘Transition radiation(TR) induced by electron–matter interaction usually demands vast accelerating voltages, and the radiation angle cannot be controlled. Here we present a mechanism of direction controllable inverse transition radiation(DCITR) in a graphene-dielectric stack excited by low-velocity electrons. The revealed mechanism shows that the induced hyperbolic-like spatial dispersion and the superposition of the individual bulk graphene plasmons(GPs) modes make the fields, which are supposed to be confined on the surface, radiate in the stack along a special radiation angle normal to the Poynting vector. By adjusting the chemical potential of the graphene sheets, the radiation angle can be controlled. And owing to the excitation of bulk GPs, only hundreds of volts for the accelerating voltage are required and the field intensity is dramatically enhanced compared with that of the normal TR. Furthermore, the presented mechanism can also be applied to the hyperbolic stack based on semiconductors in the infrared region as well as noble metals in the visible and ultraviolet region.Accordingly, the presented mechanism of DCITR is of great significance in particle detection, radiation emission,and so on.
基金This research was financially supported by Shaanxi Provincial Key Research and Development Program(Grant No.2019TSLNY01-03)National Natural Science Foundation of China(31901420)Shaanxi Science and Technology Plan Program(2019FP-023).
文摘Solar greenhouse is a typical greenhouse without any additional heating system,which has developed rapidly in Northern China.However,due to the construction quality,management methods,especially the long-term use and other factors,there are usually different degrees of thermodynamic disfigurements in the envelop enclosure of solar greenhouse.The purpose of this study was to investigate the influences of thermodynamic disfigurement on the temperature distribution and convective heat transfer of solar greenhouse.In this study,the east and west compartments of a typical solar greenhouse which is located in Yangling,China(108°4′E,34°16′N)were tested.The air temperature of each compartment was collected using temperature recorders,and the thermal infrared images of different compartment envelopes were obtained by a thermal infrared imager on a typical cloudy day.Convective heat transfer coefficients and heat flux densities of different compartment envelopes in the solar greenhouse were calculated.The results showed that the temperature difference can be displayed in the thermal infrared images of compartment envelopes,the surface temperature of the front roof was the lowest,followed by the back roof,the wall surface temperature was the highest.The minimum average surface temperature of the front roof in the eastern compartment was only 3.8℃,which was 6.8℃ and 9.2℃ lower than the average surface temperature of the back roof and back wall,respectively.The surface average temperature of thermodynamic disfigurements located at the bottom of the south side in the front roof of the eastern compartment,whose area accounted for 16.5%of the total front roof in the eastern compartment,was only 5.4℃.Compared with non-thermodynamic disfigurement,the average convective heat transfer coefficient and heat flux density of thermodynamic disfigurements in the front roof of the eastern compartment were increased by 20.3%and 110.3%,respectively.The average air temperature in the eastern compartment was 3.5℃ lower than the average air temperature in the western compartment of the solar greenhouse.Construction of brick wall at the bottom of the south side of the front roof in the solar greenhouse helped to increase the inner surface temperature of the front roof,with an average temperature rise of 6.2℃,and reduce the area of thermodynamic disfigurement,which only accounted for 2.6%of the total front roof in the western compartment.The average surface temperature of thermodynamic disfigurements mainly caused by the entry and exit door in the wall of the eastern compartment was only 9.8℃,which was lower 3.2℃ than the average temperature of non-thermodynamic disfigurement of the wall.Thermodynamic disfigurement helped to increase heat loss.The weighted average proportion of thermodynamic disfigurement in the western compartment was 2.1%,while that of thermodynamic disfigurement in the eastern compartment was 10.7%.The thermal insulation performance of the western compartment envelope in the solar greenhouse was better than that of the eastern compartment envelope.
