The hydrostatic or confining pressure of deep rocks has a significant impact on the mechanical behavior of brittle materials.Especially when confining pressure is applied,the mechanical properties of rock materials will ...The hydrostatic or confining pressure of deep rocks has a significant impact on the mechanical behavior of brittle materials.Especially when confining pressure is applied,the mechanical properties of rock materials will undergo significant changes.Considering that the process of shale sample subjected to impact load is in a closed container in the dynamic triaxial SHPB test,the failure process of the sample cannot be observed.Meanwhile,the activation volume of the shale sample would be large and local failure would occur in the test under the high strain rate loading.Therefore,thefinite element model of shale considering the bedding effect under confining pressure was established in this study.Taking shale materials with different bedding dip angles as simulation objects,the dynamic failure characteristics of shale were studied using the dynamic analysis software ANSYS/LS‐DYNA from three aspects:stress‐strain curve,failure growth process,and failure morphology.The research results obtained can serve as the key technical parameters for deep resource extraction.展开更多
Methane in-situ explosion fracturing(MISEF)enhances permeability in shale reservoirs by detonating desorbed methane to generate detonation waves in perforations.Fracture propagation in bedding shale under varying expl...Methane in-situ explosion fracturing(MISEF)enhances permeability in shale reservoirs by detonating desorbed methane to generate detonation waves in perforations.Fracture propagation in bedding shale under varying explosion loads remains unclear.In this study,prefabricated perforated shale samples with parallel and vertical bedding are fractured under five distinct explosion loads using a MISEF experimental setup.High-frequency explosion pressure-time curves were monitored within an equivalent perforation,and computed tomography scanning along with three-dimensional reconstruction techniques were used to investigate fracture propagation patterns.Additionally,the formation mechanism and influencing factors of explosion crack-generated fines(CGF)were clarified by analyzing the morphology and statistics of explosion debris particles.The results indicate that methane explosion generated oscillating-pulse loads within perforations.Explosion characteristic parameters increase with increasing initial pressure.Explosion load and bedding orientation significantly influence fracture propagation patterns.As initial pressure increases,the fracture mode transitions from bi-wing to 4–5 radial fractures.In parallel bedding shale,radial fractures noticeably deflect along the bedding surface.Vertical bedding facilitates the development of transverse fractures oriented parallel to the cross-section.Bifurcation-merging of explosioninduced fractures generated CGF.CGF mass and fractal dimension increase,while average particle size decreases with increasing explosion load.This study provides valuable insights into MISEF technology.展开更多
AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of...AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.展开更多
Alpha-trichloroacetoxy terminated polystyrene oligomer (PS-CH2CH2OCOCCl3) and poly-(styrene-b-butadiene) oligomer [P(S-b-B)-CH2CH2OCOCCl3)] were synthesized by living anionic polymeri-zation using n-butyllithium as in...Alpha-trichloroacetoxy terminated polystyrene oligomer (PS-CH2CH2OCOCCl3) and poly-(styrene-b-butadiene) oligomer [P(S-b-B)-CH2CH2OCOCCl3)] were synthesized by living anionic polymeri-zation using n-butyllithium as initiator. Then the PS-CH2CH2OCOCCl3 (PS-Cl-3) or P(S-b-B)-CH2CH2O-COCCl3 (PSB-Cl-3) was used as the macroinitiator in the polymerization of(meth)acrylates in the presence of CuX/bpy. AB diblock and ABC triblock copolymers were prepared by the integrated living anionic polymerization (LAP)-atom transfer radical polymerization (ATRP). The structures of the PSB-Cl-3 and the P(S-b-MMA) were identified by FTIR and H-1-NMR spectrum, respectively. A new way to design block copolymers (the combination of LAP and ATRP) was developed.展开更多
The subgrid-scale(SGS)kinetic energy has been used to predict the SGS stress in compressible flow and it was resolved through the SGS kinetic energy transport equation in past studies.In this paper,a new SGS eddy-visc...The subgrid-scale(SGS)kinetic energy has been used to predict the SGS stress in compressible flow and it was resolved through the SGS kinetic energy transport equation in past studies.In this paper,a new SGS eddy-viscosity model is proposed using artificial neural network to obtain the SGS kinetic energy precisely,instead of using the SGS kinetic energy equation.Using the infinite series expansion and reserving the first term of the expanded term,we obtain an approximated SGS kinetic energy,which has a high correlation with the real SGS kinetic energy.Then,the coefficient of the modelled SGS kinetic energy is resolved by the artificial neural network and the modelled SGS kinetic energy is more accurate through this method compared to the SGS kinetic energy obtained from the SGS kinetic energy equation.The coefficients of the SGS stress and SGS heat flux terms are determined by the dynamic procedure.The new model is tested in the compressible turbulent channel flow.From the a posterior tests,we know that the new model can precisely predict the mean velocity,the Reynolds stress,the mean temperature and turbulence intensities,etc.展开更多
Objective:To investigate the neuroprotective effects of Fructus Mume total flavone(FMF)against cell apoptosis and mitochondrial injury induced by 1-methyl-4-phenylpyridinium(MPP^(+))in human neuroblastoma(SH-SY5Y)cell...Objective:To investigate the neuroprotective effects of Fructus Mume total flavone(FMF)against cell apoptosis and mitochondrial injury induced by 1-methyl-4-phenylpyridinium(MPP^(+))in human neuroblastoma(SH-SY5Y)cells and explore its molecular mechanisms.Methods:MPP^(+) induced SH-SY5Y cells injury model were established in vitro cell culture,the cells were divided into 5 groups:normal control group,model group(250μmol·L^(-1) MPP^(+)),FMF low-and middle-and high-dose experimental group(10,50,100μmol·L^(-1) FMF).After 72 h administration,4’,6-diamidino-2-phenylindole(DAPI)staining was used to observe the effects of different concentrations of FMF on the morphologic changes of apoptotic cells,the ratio of cell apoptosis was measured by Annexin-FITC/PI double staining.The mitochondrial membrane electro-bit were detected by flow cytometry(FCM).The expression of Bcl-2,Bax and Caspase-3 were detected by Western blot.Results:The results of DAPI staining showed that the injury SH-SY5Y cells induced by MPP+were densely condensed,the nucleus showed nuclear shrinkage,showing an apoptotic characteristic morphology;after 72h of FMF action,the apoptotic morphology of the cells showed different degrees of improvement,and the apoptotic number of SH-SY5Y cells also decreased.Compared with that in the normal control group,the apoptotic rate and of mitochondrial membrane electrobit of SH-SY5Y cells in the model group increased significantly(P<0.01),the expression of Bax and Caspase-3 proteins increased significantly(P<0.01),Bcl-2 protein and the ratio of Bcl-2/Bax decreased significantly(P<0.01).Compared with that in the model group,the apoptotic rate and mitochondrial membrane electro-bit of SH-SY5Y cells in FMF groups(10,50,100μmol·L^(-1))were significantly lower,while Bax and Caspase-3 proteins were significantly lower(P<0.01),and Bcl-2 protein and the ratio of Bcl-2/Bax were significantly higher,with statistically significant difference in FMF middle-and high-dose experimental groups(P<0.01).The results indicated that FMF can decrease the experession level of Bax and Caspase-3 and increase the ratio of Bcl-2/Bax,inhibit MPP+induced apoptosis.Conclusion:FMF improves the damage of SH-SY5Y cells induced by MPP+,and plays a neuroprotective effect by regulating the expressions of related proteins in mitochondrial apoptosis pathway.展开更多
[Objectives]Industrial prosperity is an important part of implementing rural revitalization strategy,and promoting the transformation and upgrading of the agricultural industry has strong practical significance for th...[Objectives]Industrial prosperity is an important part of implementing rural revitalization strategy,and promoting the transformation and upgrading of the agricultural industry has strong practical significance for the development of high-quality agriculture and the construction of a modern agricultural industry system.[Methods]Based on the overview of agricultural production in Xixia County from 2012 to 2018,the status,advantages and main problems of the agricultural industry development in the county are sorted out.[Results]The fruit-medicine-fungus featured agriculture has begun to take shape,and the effect of industrial clusters and large-scale operations has begun to become prominent.The output of shiitake mushrooms,Chinese patent medicines and kiwifruit all shows a steady growth trend.Excellent varieties,brand building,and deep integration of the three industries are the key factors for the development of agricultural industrialization.[Conclusions]In the context of the implementation of the rural revitalization strategy,countermeasures and suggestions on the development of ecological green agriculture,high-quality agriculture,brand agriculture,and modern agricultural management system are put forward.展开更多
The two dimensional Lattice Gas Automation (LGA) was applied to simulate the current flow in saturated digital rock for revealing the effects of micro structure and saturation on the electrical transport properties. T...The two dimensional Lattice Gas Automation (LGA) was applied to simulate the current flow in saturated digital rock for revealing the effects of micro structure and saturation on the electrical transport properties. The digital rock involved in this research can be constructed by the pile of matrix grain with radius obtained from the SEM images of rock sections. We further investigate the non-Archie phenomenon with the LGA and compare micro-scale numerical modeling with laboratory measurements. Based on results, a more general model has been developed for reservoir evaluation of saturation with higher accuracy in oilfield application. The calculations from the new equation show very good agreement with laboratory measurements and published data on sandstone samples.展开更多
To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed...To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed that the dry and wet deposition fluxes of total nitrogen(TN)during the monitoring period were 6.87 and 6.46 kg/(hm^(2)·a),respectively.The ratio of wet to dry deposition of TN was approximately 1∶1,with wet deposition being dominated by ammonium nitrogen deposition.The dry and wet deposition fluxes of total phosphorus(TP)were 0.228 and 0.125 kg/(hm^(2)·a),and it was dominated by dry deposition.The average concentration of TN in wet deposition exceeded the standard threshold for eutrophic waters,and its ecological effects on the Baiyangdian basin should be concerned.Wet deposition fluxes of nitrogen and phosphorus had a significantly positive correlation with rainfall,while their deposition concentrations were negatively correlated with rainfall.The dry deposition of atmospheric nitrogen and phosphorus was influenced by the amount of dustfall and climatic factors such as rainfall,temperature,and humidity,which mainly occurred from April to August.展开更多
Illegal construction has caused serious harm around the world. However, current methods are difficult to detect illegal construction activities in time, and the calculation complexity and the parameters of them are la...Illegal construction has caused serious harm around the world. However, current methods are difficult to detect illegal construction activities in time, and the calculation complexity and the parameters of them are large. To solve these challenges, a new and unique detection method is proposed, which detects objects related to illegal buildings in time to discover illegal construction activities. Meanwhile, a new dataset and a high-precision and lightweight detector are proposed. The proposed detector is based on the algorithm You Only Look Once (YOLOv4). The use of DenseNet as the backbone of YDHNet enables better feature transfer and reuse, improves detection accuracy, and reduces computational costs. Meanwhile, depthwise separable convolution is employed to lightweight the neck and head to further reduce computational costs. Furthermore, H-swish is utilized to enhance non-linear feature extraction and improve detection accuracy. Experimental results illustrate that YDHNet realizes a mean average precision of 89.60% on the proposed dataset, which is 3.78% higher than YOLOv4. The computational cost and parameter count of YDHNet are 26.22 GFLOPs and 16.18 MB, respectively. Compared to YOLOv4 and other detectors, YDHNet not only has lower computational costs and higher detection accuracy, but also timely identifies illegal construction objects and automatically detects illegal construction activities.展开更多
In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo ...In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo modification on enhanced catalytic performance was explored.Among Mn Co-BTC@SiO_(2-x) catalysts with different HPMo concentrations,Mn CoBTC@SiO_(2)-0.75 catalyst exhibited not only the highest NH_(3)-SCR performance(95% at 200-300℃)but also the best N_(2)selectivity(exceed 80% at 100-300℃)due to the appropriate redox capacity,greater surface acidity.X-ray photoelectron spectrometer(XPS)and temperature programmed reduction of H_(2)(H_(2)-TPR)results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo^(5+)to Mn^(4+)/Mn^(3+)and prevent the excessive oxidation of ammonia adsorption species.NH_(3)temperature-programmed desorption of(NH_(3)-TPD)results showed that the modification with HPMo could significantly improve the surface acidity and NH_(3)adsorption,which enhance the catalytic activity and N_(2)selectivity.In-situ diffused reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)revealed that modification with HPMo increased significantly the amount of adsorbed NH_(3)species on the Bronsted acid site and C_(B)/C_(L),it suppressed the production of N_(2)O by inhibiting the production of NH species,the deep dehydrogenation of ammonia adsorption species.This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N_(2)selectivity.展开更多
The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive.In this paper,a resource application of chlorella was proposed,and a Chlorella@Mn composite denitrification ...The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive.In this paper,a resource application of chlorella was proposed,and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic interaction.The Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions(0.54 g/L Mn^(2+)concentration,20 million chlorellas/mL concentration,450℃ calcination temperature)exhibited a well-developed pore structure and large specific surface area(122 m^(2)/g).Compared with MnOx alone,the Chlorella@Mn composite catalyst achieved superior performance,with~100%NH_(3)selective catalytic reduction(NH_(3)-SCR)denitrification activity at 100-225℃.The results of NH_(3)temperature-programmed desorption(NH_(3)-TPD)and H_(2)temperature-programmed reduction(H_(2)-TPR)showed that the catalyst had strong acid sites and good redox properties.Zeta potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn^(2+).X-ray photoelectron spectroscopy(XPS)confirmed that Chlorella@Mn had a high content of Mn^(3+)and surface chemisorbed oxygen.In-situ diffuse refectance infrared Fourier transform spectroscopy(in-situ DRIFTS)experimental results showed that both Langmuir-Hinshelwood(L-H)and Eley-Rideal(E-R)mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst,where the main intermediate nitrate species is monodentate nitrite.The presence of SO_(2)promoted the generation and strengthening of Bronsted acid sites,but also generated more sulfate species on the surface,thereby reducing the denitrification activity of the Chlorella@Mn catalyst.The Chlorella@Mn composite catalyst had the characteristics of short preparation time,simple process and low cost,making it promising for industrial application.展开更多
The electrochromic(EC)mechanisms of inorganic materials are usually based on reversible cation insertion/extraction or metal deposition/dissolution,which are plagued by ion trapping and dendrite growth,respectively.In...The electrochromic(EC)mechanisms of inorganic materials are usually based on reversible cation insertion/extraction or metal deposition/dissolution,which are plagued by ion trapping and dendrite growth,respectively.In this paper,a novel conversion-type electrochromic mechanism is proposed,by making good use of the CuI/Cu redox couple.This CuI-based electrochromic system shows a neutral color switching from transparent and dim grey.By simply increasing the bleaching voltage,I_(3)^(-)/I^(-)redox couple can be further activated.The generated I_(3)^(-)will readily react with Cu,effectively improving the conversion reversibility and thereby rejuvenating the degraded electrochromic performance.Thanks to the well-designed electrode and the self-healing ability,this conversion electrochromic system achieves rapid response times(tcoloring:23 s,tbleaching:6 s),decant optical modulation amplitude(26.4%),high coloration efficiency(86.15 cm^(2)·C^(-1)),admirable cyclic durability(without performance degradation after 480 cycles)and excellent optical memory ability(transmittance variation<1%after 10 h open-circuit storage).The establishment of this conversion-type electrochromism may inspire the exploration of novel electrochromic materials and devices.展开更多
Active distribution network(ADN)is a solution for power system with interconnection of distributed energy resources(DER),which may change the network operation and power flow of traditional power distribution network....Active distribution network(ADN)is a solution for power system with interconnection of distributed energy resources(DER),which may change the network operation and power flow of traditional power distribution network.However,in some circumstances the malfunction of protection and feeder automation in distribution network occurs due to the uncertain bidirectional power flow.Therefore,a novel method of fault location,isolation,and service restoration(FLISR)for ADN based on distributed processing is proposed in this paper.The differential-activated algorithm based on synchronous sampling for feeder fault location and isolation is studied,and a framework of fault restoration is established for ADN.Finally,the effectiveness of the proposed algorithm is verified via computer simulation of a case study for active distributed power system.展开更多
Under harsh conditions (such as high temperature, high pressure, and millisecond lifetime chemical reaction), a long-standing challenge remains to accurately predict the growth characteristics of nanosize spherical ...Under harsh conditions (such as high temperature, high pressure, and millisecond lifetime chemical reaction), a long-standing challenge remains to accurately predict the growth characteristics of nanosize spherical particles and to determine the rapid chemical reaction flow field characteristics, The growth characteristics of similar spherical oxide nanoparticles are further studied by successfully introducing the space-time conservation element-solution element (CE/SE) algorithm with the monodisperse Kruis model. This approach overcomes the nanosize particle rapid growth limit set and successfully captures the characteristics of the rapid gaseous chemical reaction process. The results show that this approach quantitatively captures the characteristics of the rapid chemical reaction, nanosize particle growth and size distribution. To reveal the growth mechanism for numerous types of oxide nanoparticles, it is very important to choose a rational numerical method and particle physics model.展开更多
基金National Key Research and Development Project of China,Grant/Award Number:2020YFA0711800National Natural Science Foundation of China,Grant/Award Numbers:12072363,12372373。
文摘The hydrostatic or confining pressure of deep rocks has a significant impact on the mechanical behavior of brittle materials.Especially when confining pressure is applied,the mechanical properties of rock materials will undergo significant changes.Considering that the process of shale sample subjected to impact load is in a closed container in the dynamic triaxial SHPB test,the failure process of the sample cannot be observed.Meanwhile,the activation volume of the shale sample would be large and local failure would occur in the test under the high strain rate loading.Therefore,thefinite element model of shale considering the bedding effect under confining pressure was established in this study.Taking shale materials with different bedding dip angles as simulation objects,the dynamic failure characteristics of shale were studied using the dynamic analysis software ANSYS/LS‐DYNA from three aspects:stress‐strain curve,failure growth process,and failure morphology.The research results obtained can serve as the key technical parameters for deep resource extraction.
基金funded by the National Key Research and Development Program of China(No.2020YFA0711800)the National Science Fund for Distinguished Young Scholars(No.51925404)+2 种基金the National Natural Science Foundation of China(No.12372373)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX24_2909)the Graduate Innovation Program of China University of Mining and Technology(No.2024WLKXJ134)。
文摘Methane in-situ explosion fracturing(MISEF)enhances permeability in shale reservoirs by detonating desorbed methane to generate detonation waves in perforations.Fracture propagation in bedding shale under varying explosion loads remains unclear.In this study,prefabricated perforated shale samples with parallel and vertical bedding are fractured under five distinct explosion loads using a MISEF experimental setup.High-frequency explosion pressure-time curves were monitored within an equivalent perforation,and computed tomography scanning along with three-dimensional reconstruction techniques were used to investigate fracture propagation patterns.Additionally,the formation mechanism and influencing factors of explosion crack-generated fines(CGF)were clarified by analyzing the morphology and statistics of explosion debris particles.The results indicate that methane explosion generated oscillating-pulse loads within perforations.Explosion characteristic parameters increase with increasing initial pressure.Explosion load and bedding orientation significantly influence fracture propagation patterns.As initial pressure increases,the fracture mode transitions from bi-wing to 4–5 radial fractures.In parallel bedding shale,radial fractures noticeably deflect along the bedding surface.Vertical bedding facilitates the development of transverse fractures oriented parallel to the cross-section.Bifurcation-merging of explosioninduced fractures generated CGF.CGF mass and fractal dimension increase,while average particle size decreases with increasing explosion load.This study provides valuable insights into MISEF technology.
基金Supported by National Natural Science Foundation of China, No. 30570665the Foundation of Dalian Technology Bureau, No. 2008E13SF182the Foundation of Key Laboratory of Education Department of Liaoning Province,No. 2009S005
文摘AIM: To investigate whether nicotinamide overload plays a role in type 2 diabetes. METHODS: Nicotinamide metabolic patterns of 14 diabetic and 14 non-diabetic subjects were compared using HPLC. Cumulative effects of nicotinamide and N^1-methylnicotinamide on glucose metabolism, plasma HzO2 levels and tissue nicotinamide adenine dinucleotide (NAD) contents of adult Sprague-Dawley rats were observed. The role of human sweat glands and rat skin in nicotinamide metabolism was investigated using sauna and burn injury, respectively. RESULTS: Diabetic subjects had significantly higher plasma N^1-methylnicotinamide levels 5 h after a 100-mg nicotinamide load than the non-diabetic subjects (0.89 ± 0.13 μmol/L vs 0.6 ± 0.13 μmol/L, P 〈 0.001). Cumulative doses of nicotinamide (2 g/kg) significantly increased rat plasma Nl-methylnicotinamide concentrations associated with severe insulin resistance, which was mimicked by Nl-methy-Inicotinamide. Moreover, cumulative exposure to N^1- methylnicotinamide (2 g/kg) markedly reduced rat muscle and liver NAD contents and erythrocyte NAD/ NADH ratio, and increased plasma H2O2 levels. Decrease in NAD/NADH ratio and increase in H2O2 generation were also observed in human erythrocytes after exposure to N^1-methylnicotinamide in vitro. Sweating eliminated excessive nicotinamide (5.3-fold increase in sweat nicotinamide concentration 1 h after a 100-mg nicotinamide load). Skin damage or aldehyde oxidase inhibition with tamoxifen or olanzapine, both being notorious for impairing glucose tolerance, delayed N^1- methylnicotinamide clearance. CONCLUSION: These findings suggest that nicotinamide overload, which induced an increase in plasma N^1- methylnicotinamide, associated with oxidative stress and insulin resistance, plays a role in type 2 diabetes.
基金The Project is supported by the National Natural Science Foundation of China (Grant No. 29634010-2), Shanghai Education Development Foundation Shuguang Program (Project SG97008) and Research Institute of Beijing Yanshan Petrochemical Corporation.
文摘Alpha-trichloroacetoxy terminated polystyrene oligomer (PS-CH2CH2OCOCCl3) and poly-(styrene-b-butadiene) oligomer [P(S-b-B)-CH2CH2OCOCCl3)] were synthesized by living anionic polymeri-zation using n-butyllithium as initiator. Then the PS-CH2CH2OCOCCl3 (PS-Cl-3) or P(S-b-B)-CH2CH2O-COCCl3 (PSB-Cl-3) was used as the macroinitiator in the polymerization of(meth)acrylates in the presence of CuX/bpy. AB diblock and ABC triblock copolymers were prepared by the integrated living anionic polymerization (LAP)-atom transfer radical polymerization (ATRP). The structures of the PSB-Cl-3 and the P(S-b-MMA) were identified by FTIR and H-1-NMR spectrum, respectively. A new way to design block copolymers (the combination of LAP and ATRP) was developed.
基金supported by the National Key Research and Development Program of China(Grant Nos.2020YFA0711800,2019YFA0405302)NSFC Projects(Grant Nos.12072349,91852203)+1 种基金National Numerical Windtunnel Project,Science Challenge Project(Grant No.TZ2016001)Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDC01000000).
文摘The subgrid-scale(SGS)kinetic energy has been used to predict the SGS stress in compressible flow and it was resolved through the SGS kinetic energy transport equation in past studies.In this paper,a new SGS eddy-viscosity model is proposed using artificial neural network to obtain the SGS kinetic energy precisely,instead of using the SGS kinetic energy equation.Using the infinite series expansion and reserving the first term of the expanded term,we obtain an approximated SGS kinetic energy,which has a high correlation with the real SGS kinetic energy.Then,the coefficient of the modelled SGS kinetic energy is resolved by the artificial neural network and the modelled SGS kinetic energy is more accurate through this method compared to the SGS kinetic energy obtained from the SGS kinetic energy equation.The coefficients of the SGS stress and SGS heat flux terms are determined by the dynamic procedure.The new model is tested in the compressible turbulent channel flow.From the a posterior tests,we know that the new model can precisely predict the mean velocity,the Reynolds stress,the mean temperature and turbulence intensities,etc.
基金National Natural Science Foundation of China Project(No.82060888)Approved Project of Guangxi Health Department(No.Z2016220)Approved Project of Guangxi Administration of Traditional Chinese Medicine(No.GZZC2020107)。
文摘Objective:To investigate the neuroprotective effects of Fructus Mume total flavone(FMF)against cell apoptosis and mitochondrial injury induced by 1-methyl-4-phenylpyridinium(MPP^(+))in human neuroblastoma(SH-SY5Y)cells and explore its molecular mechanisms.Methods:MPP^(+) induced SH-SY5Y cells injury model were established in vitro cell culture,the cells were divided into 5 groups:normal control group,model group(250μmol·L^(-1) MPP^(+)),FMF low-and middle-and high-dose experimental group(10,50,100μmol·L^(-1) FMF).After 72 h administration,4’,6-diamidino-2-phenylindole(DAPI)staining was used to observe the effects of different concentrations of FMF on the morphologic changes of apoptotic cells,the ratio of cell apoptosis was measured by Annexin-FITC/PI double staining.The mitochondrial membrane electro-bit were detected by flow cytometry(FCM).The expression of Bcl-2,Bax and Caspase-3 were detected by Western blot.Results:The results of DAPI staining showed that the injury SH-SY5Y cells induced by MPP+were densely condensed,the nucleus showed nuclear shrinkage,showing an apoptotic characteristic morphology;after 72h of FMF action,the apoptotic morphology of the cells showed different degrees of improvement,and the apoptotic number of SH-SY5Y cells also decreased.Compared with that in the normal control group,the apoptotic rate and of mitochondrial membrane electrobit of SH-SY5Y cells in the model group increased significantly(P<0.01),the expression of Bax and Caspase-3 proteins increased significantly(P<0.01),Bcl-2 protein and the ratio of Bcl-2/Bax decreased significantly(P<0.01).Compared with that in the model group,the apoptotic rate and mitochondrial membrane electro-bit of SH-SY5Y cells in FMF groups(10,50,100μmol·L^(-1))were significantly lower,while Bax and Caspase-3 proteins were significantly lower(P<0.01),and Bcl-2 protein and the ratio of Bcl-2/Bax were significantly higher,with statistically significant difference in FMF middle-and high-dose experimental groups(P<0.01).The results indicated that FMF can decrease the experession level of Bax and Caspase-3 and increase the ratio of Bcl-2/Bax,inhibit MPP+induced apoptosis.Conclusion:FMF improves the damage of SH-SY5Y cells induced by MPP+,and plays a neuroprotective effect by regulating the expressions of related proteins in mitochondrial apoptosis pathway.
基金Soft Science Project of Henan Province(192400410130).
文摘[Objectives]Industrial prosperity is an important part of implementing rural revitalization strategy,and promoting the transformation and upgrading of the agricultural industry has strong practical significance for the development of high-quality agriculture and the construction of a modern agricultural industry system.[Methods]Based on the overview of agricultural production in Xixia County from 2012 to 2018,the status,advantages and main problems of the agricultural industry development in the county are sorted out.[Results]The fruit-medicine-fungus featured agriculture has begun to take shape,and the effect of industrial clusters and large-scale operations has begun to become prominent.The output of shiitake mushrooms,Chinese patent medicines and kiwifruit all shows a steady growth trend.Excellent varieties,brand building,and deep integration of the three industries are the key factors for the development of agricultural industrialization.[Conclusions]In the context of the implementation of the rural revitalization strategy,countermeasures and suggestions on the development of ecological green agriculture,high-quality agriculture,brand agriculture,and modern agricultural management system are put forward.
文摘The two dimensional Lattice Gas Automation (LGA) was applied to simulate the current flow in saturated digital rock for revealing the effects of micro structure and saturation on the electrical transport properties. The digital rock involved in this research can be constructed by the pile of matrix grain with radius obtained from the SEM images of rock sections. We further investigate the non-Archie phenomenon with the LGA and compare micro-scale numerical modeling with laboratory measurements. Based on results, a more general model has been developed for reservoir evaluation of saturation with higher accuracy in oilfield application. The calculations from the new equation show very good agreement with laboratory measurements and published data on sandstone samples.
文摘To study the characteristics of atmospheric dry and wet deposition in the upper reaches of Baiyangdian,two sampling sites in Baoding City were monitored for 1 year from September 2018 to August 2019.The results showed that the dry and wet deposition fluxes of total nitrogen(TN)during the monitoring period were 6.87 and 6.46 kg/(hm^(2)·a),respectively.The ratio of wet to dry deposition of TN was approximately 1∶1,with wet deposition being dominated by ammonium nitrogen deposition.The dry and wet deposition fluxes of total phosphorus(TP)were 0.228 and 0.125 kg/(hm^(2)·a),and it was dominated by dry deposition.The average concentration of TN in wet deposition exceeded the standard threshold for eutrophic waters,and its ecological effects on the Baiyangdian basin should be concerned.Wet deposition fluxes of nitrogen and phosphorus had a significantly positive correlation with rainfall,while their deposition concentrations were negatively correlated with rainfall.The dry deposition of atmospheric nitrogen and phosphorus was influenced by the amount of dustfall and climatic factors such as rainfall,temperature,and humidity,which mainly occurred from April to August.
基金supported in part by the National Natural Science Foundation of China(Nos.62177034 and 61972046).
文摘Illegal construction has caused serious harm around the world. However, current methods are difficult to detect illegal construction activities in time, and the calculation complexity and the parameters of them are large. To solve these challenges, a new and unique detection method is proposed, which detects objects related to illegal buildings in time to discover illegal construction activities. Meanwhile, a new dataset and a high-precision and lightweight detector are proposed. The proposed detector is based on the algorithm You Only Look Once (YOLOv4). The use of DenseNet as the backbone of YDHNet enables better feature transfer and reuse, improves detection accuracy, and reduces computational costs. Meanwhile, depthwise separable convolution is employed to lightweight the neck and head to further reduce computational costs. Furthermore, H-swish is utilized to enhance non-linear feature extraction and improve detection accuracy. Experimental results illustrate that YDHNet realizes a mean average precision of 89.60% on the proposed dataset, which is 3.78% higher than YOLOv4. The computational cost and parameter count of YDHNet are 26.22 GFLOPs and 16.18 MB, respectively. Compared to YOLOv4 and other detectors, YDHNet not only has lower computational costs and higher detection accuracy, but also timely identifies illegal construction objects and automatically detects illegal construction activities.
基金supported by the National Natural Science Foundation of China(No.U20A20130 and 21806009)the Fundamental Research Funds for the Central Universities(No.FRF-IDRY-19-020)。
文摘In this work,the phosphomolybdate(HPMo)modification strategy was applied to improve the N_(2) selectivity of Mn Co-BTC@SiO_(2)catalyst for the selective catalytic reduction of NO_(x),and further,the mechanism of HPMo modification on enhanced catalytic performance was explored.Among Mn Co-BTC@SiO_(2-x) catalysts with different HPMo concentrations,Mn CoBTC@SiO_(2)-0.75 catalyst exhibited not only the highest NH_(3)-SCR performance(95% at 200-300℃)but also the best N_(2)selectivity(exceed 80% at 100-300℃)due to the appropriate redox capacity,greater surface acidity.X-ray photoelectron spectrometer(XPS)and temperature programmed reduction of H_(2)(H_(2)-TPR)results showed that the modification with HPMo reduced the oxidation-reduction performance of the catalyst due to electron transfer from Mo^(5+)to Mn^(4+)/Mn^(3+)and prevent the excessive oxidation of ammonia adsorption species.NH_(3)temperature-programmed desorption of(NH_(3)-TPD)results showed that the modification with HPMo could significantly improve the surface acidity and NH_(3)adsorption,which enhance the catalytic activity and N_(2)selectivity.In-situ diffused reflectance infrared Fourier transform spectroscopy(in-situ DRIFTS)revealed that modification with HPMo increased significantly the amount of adsorbed NH_(3)species on the Bronsted acid site and C_(B)/C_(L),it suppressed the production of N_(2)O by inhibiting the production of NH species,the deep dehydrogenation of ammonia adsorption species.This study provided a simple design strategy for the catalyst to improve the low-temperature catalytic performance and N_(2)selectivity.
基金supported by the National Natural Science Foundation of China (No.U20A20130)the Fundamental Research Funds for the Central Universities (No.FRF-TP-20-03B)。
文摘The synthesis process of conventional Mn-based denitrification catalysts is relatively complex and expensive.In this paper,a resource application of chlorella was proposed,and a Chlorella@Mn composite denitrification catalyst was innovatively synthesized by electrostatic interaction.The Chlorella@Mn composite denitrification catalyst prepared under the optimal conditions(0.54 g/L Mn^(2+)concentration,20 million chlorellas/mL concentration,450℃ calcination temperature)exhibited a well-developed pore structure and large specific surface area(122 m^(2)/g).Compared with MnOx alone,the Chlorella@Mn composite catalyst achieved superior performance,with~100%NH_(3)selective catalytic reduction(NH_(3)-SCR)denitrification activity at 100-225℃.The results of NH_(3)temperature-programmed desorption(NH_(3)-TPD)and H_(2)temperature-programmed reduction(H_(2)-TPR)showed that the catalyst had strong acid sites and good redox properties.Zeta potential testing showed that the electronegativity of the chlorella cell surface could be used to enrich with Mn^(2+).X-ray photoelectron spectroscopy(XPS)confirmed that Chlorella@Mn had a high content of Mn^(3+)and surface chemisorbed oxygen.In-situ diffuse refectance infrared Fourier transform spectroscopy(in-situ DRIFTS)experimental results showed that both Langmuir-Hinshelwood(L-H)and Eley-Rideal(E-R)mechanisms play a role in the denitrification process on the surface of the Chlorella@Mn catalyst,where the main intermediate nitrate species is monodentate nitrite.The presence of SO_(2)promoted the generation and strengthening of Bronsted acid sites,but also generated more sulfate species on the surface,thereby reducing the denitrification activity of the Chlorella@Mn catalyst.The Chlorella@Mn composite catalyst had the characteristics of short preparation time,simple process and low cost,making it promising for industrial application.
基金the National Natural Science Foundation of China(Nos.52371238,22273081,52207249)the Natural Science Foundation of Shandong Province(No.ZR2020ME024)+1 种基金Taishan Young Scholar Program(No.tsqn202211114)the Open Foundation of Key Laboratory for Palygorskite Science and Applied Technology of Jiangsu Province(No.HPK202103)for financial support.
文摘The electrochromic(EC)mechanisms of inorganic materials are usually based on reversible cation insertion/extraction or metal deposition/dissolution,which are plagued by ion trapping and dendrite growth,respectively.In this paper,a novel conversion-type electrochromic mechanism is proposed,by making good use of the CuI/Cu redox couple.This CuI-based electrochromic system shows a neutral color switching from transparent and dim grey.By simply increasing the bleaching voltage,I_(3)^(-)/I^(-)redox couple can be further activated.The generated I_(3)^(-)will readily react with Cu,effectively improving the conversion reversibility and thereby rejuvenating the degraded electrochromic performance.Thanks to the well-designed electrode and the self-healing ability,this conversion electrochromic system achieves rapid response times(tcoloring:23 s,tbleaching:6 s),decant optical modulation amplitude(26.4%),high coloration efficiency(86.15 cm^(2)·C^(-1)),admirable cyclic durability(without performance degradation after 480 cycles)and excellent optical memory ability(transmittance variation<1%after 10 h open-circuit storage).The establishment of this conversion-type electrochromism may inspire the exploration of novel electrochromic materials and devices.
基金This paper was supported by the National High Technology Research and Development Program of China(863 Program)(No.2014AA051902).
文摘Active distribution network(ADN)is a solution for power system with interconnection of distributed energy resources(DER),which may change the network operation and power flow of traditional power distribution network.However,in some circumstances the malfunction of protection and feeder automation in distribution network occurs due to the uncertain bidirectional power flow.Therefore,a novel method of fault location,isolation,and service restoration(FLISR)for ADN based on distributed processing is proposed in this paper.The differential-activated algorithm based on synchronous sampling for feeder fault location and isolation is studied,and a framework of fault restoration is established for ADN.Finally,the effectiveness of the proposed algorithm is verified via computer simulation of a case study for active distributed power system.
基金This research was financially supported by the National Natural Science Foundation of China (No. 11502282), the China Scholarship Council Fund (No. 201506425040), the Natural Science Foundation of Jiangsu Province (No. BK20140178).
文摘Under harsh conditions (such as high temperature, high pressure, and millisecond lifetime chemical reaction), a long-standing challenge remains to accurately predict the growth characteristics of nanosize spherical particles and to determine the rapid chemical reaction flow field characteristics, The growth characteristics of similar spherical oxide nanoparticles are further studied by successfully introducing the space-time conservation element-solution element (CE/SE) algorithm with the monodisperse Kruis model. This approach overcomes the nanosize particle rapid growth limit set and successfully captures the characteristics of the rapid gaseous chemical reaction process. The results show that this approach quantitatively captures the characteristics of the rapid chemical reaction, nanosize particle growth and size distribution. To reveal the growth mechanism for numerous types of oxide nanoparticles, it is very important to choose a rational numerical method and particle physics model.