Highland barley(HB)is a high-altitude cereal with rich nutritional components and potential health benefits.To clarify its hypoglycemic effect and mechanism,we investigated the effect of whole grain HB and fecal micro...Highland barley(HB)is a high-altitude cereal with rich nutritional components and potential health benefits.To clarify its hypoglycemic effect and mechanism,we investigated the effect of whole grain HB and fecal microbiota transplantation(FMT)on glucose metabolism and gut microbiota in high-fat diet and streptozotocin(HFD/STZ)-induced diabetic mice.The results showed that HB(40%)significantly decreased fasting blood glucose and the area under the glucose tolerance curve,significantly increased insulin secretion and improved insulin resistance in HFD/STZ-induced diabetic mice(P<0.05).Inflammatory factors and blood lipid indices were also significantly alleviated after 12 weeks of 40%HB intervention(P<0.05).Additionally,beneficial bacteria,such as Bifidobacterium and Akkermansia,were significantly enriched in the gut of diabetic mice after whole grain HB intervention.Meanwhile,the results of further FMT experiments verified that the fecal microbiota after the 40%HB intervention not only significantly increased the relative abundance of Bifidobacterium and Akkermansia but also effectively improved glucose metabolism and alleviated the inflammatory state in HFD/STZ-induced diabetic mice.Collectively,our study confirmed the bridge role of gut microbiota in improving glucose metabolism of whole grain HB,which could promote the development of precision nutrition.展开更多
Carbyne delivers various excellent properties for the existence of the larger number of sp-hybridized carbon atoms.Here,a 3D well-defined porous carbon material germanium-carbdiyne(Ge-CDY)which is comprised of only sp...Carbyne delivers various excellent properties for the existence of the larger number of sp-hybridized carbon atoms.Here,a 3D well-defined porous carbon material germanium-carbdiyne(Ge-CDY)which is comprised of only sp-hybridized carbon atoms bridging by Ge atoms has been developed and investigated.The unique diamond-like structure constructed by linear butadiyne bonds and sp 3-hybridized Ge atoms ensures the stability of Ge-CDY.The large percentage of conjugated alkyne bonds composed of sp-C guarantees the good conductivity and the low band gap,which were further confirmed experimentally and theoretically,endowing Ge-CDY with the potential in electrochemical applications.The well-defined 3D carbon skeleton of Ge-CDY provides abundant uniform nanopores,which is suitable for metal ions storage and diffusion.Further half-cell evaluation also demonstrated Ge-CDY exhibited an excellent performance in lithium storage.All those indicating sp-hybridized carbon-based materials can exhibit great potential to possess excellent properties and be applied in the field of energy,electronic,and so on.展开更多
A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this...A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this paper,the stress analysis of the main cable is carried out,and the relationship between the slope change and the coordinate change is found.This paper also discussed how to find the minimum slope point of symmetrical or asymmetric main cable,and the deformation compatibility equation is established and solved to obtain the shape of main cable.The algorithm in this paper can ensure the convergence of the solution for the suspension bridge with spatial cables.The calculation accuracy is high through the demonstration of the calculation examples.展开更多
China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface ...China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface for this mission based on orbital remotesensing data.We constructed a geomorphologic map for the Tianwen-1 landing area.Results of our detailed geomorphologic map show several major landforms within the landing area,including rampart craters,mesas,troughs,cones,and ridges.Analysis of materials on the landing area surface indicates that most of the landing area is covered by Martian dust.Transverse aeolian ridges are widely distributed within the landing area,indicating the surface contexts were(and still are)modified by regional winds.In addition,a crater counting analysis indicates the landing area has an absolute model age of~3.3 Ga and that a later resurfacing event occurred at~1.6 Ga.Finally,we outline four formational scenarios to test the formation mechanisms for the geomorphologic features on the landing area surface.The most likely interpretation to explain the existence of the observed surface features can be summarized as follows:A thermal influence may have played an important role in the formation of the surface geomorphologic features;thus,igneous-related processes may have occurred in the landing area.Water ice may also have been involved in the construction of the primordial surface configuration.Subsequent resurfacing events and aeolian processes buried and modified the primordial surface.展开更多
The Chang’E-6 mission will first land on the far side of the moon and bring lunar samples back.As a hyperspectral imager aboard the Chang’E-6 lander,the Lunar Mineralogical Spectrometer(LMS),will achieve the goal of...The Chang’E-6 mission will first land on the far side of the moon and bring lunar samples back.As a hyperspectral imager aboard the Chang’E-6 lander,the Lunar Mineralogical Spectrometer(LMS),will achieve the goal of spectral detection and mineral composition analysis in the sampling area,and the data of LMS will also be compared with the results of the returned sample laboratory measurements.Visible and near-infrared hyperspectral remote sensing is an effective tool for lunar minerals identification and quantification.The ground validation experiment can be used to evaluate the detection ability of the LMS.According to the modal abundances of lunar minerals and glasses of APOLLO samples,binary mixed samples,ternary mixed samples,and seven-membered mixed samples were prepared.The samples were ground and stirred homogeneous to about 200 mesh(median particle size about 75μm),to simulate the soil state of the lunar surface.Under the laboratory ambient condition,the 480–3200 nm spectral data of the samples were acquired using the Engineering Qualification Model(EQM)of Chang’E-5 LMS,the performance of which is consistent with the flight model of Chang’E-6 LMS.By fitting the mixed samples’spectral data of the EQM using the Modified Gaussian Methods,the following conclusions can be drawn:The subtle spectral changes of mixed samples can be detected.The modal abundance of low-Ca pyroxene,high-Ca pyroxene,and plagioclase can be derived based on the spectral parameters such as absorption position,depth or width of the mixed samples,and the correlation coefficients R2are better than 82%,indicating that the LMS has good quantitative detection capability.展开更多
Rechargeable Mg batteries(RMBs)are a promising large-scale energy-storage technology with low cost and high safety,but the performance is limited by the inferior kinetics of Mg-intercalation cathodes.In the present st...Rechargeable Mg batteries(RMBs)are a promising large-scale energy-storage technology with low cost and high safety,but the performance is limited by the inferior kinetics of Mg-intercalation cathodes.In the present study,an octylamine-supporting interlayer expanded molybdenum diselenide(e-MoSe_(2))is synthesized and used as cathode for RMBs,in comparison with ordinary crystalline MoSe_(2).The octylamine molecules introduced show a strong interaction with the MoSe_(2)layers and increase the layer spacing significantly from 6.46 to 11.5Å.e-MoSe_(2)shows a high Mg-storage capacity of 238 mAh g^(-1)at 50 mA g^(-1)and a superior rate performance of 39 mAh g^(-1)at 10 A g1,far advantageous over crystalline MoSe_(2).e-MoSe_(2)also shows a considerably high structure stability during repeated magnesiation/demagnesiation,providing an outstanding cycling stability for 1000 cycles.Further electrochemical tests demonstrate the high Mg^(2+)diffusion coefficients in e-MoSe_(2).Theoretical computation indicates the interlayer expansion changes the Mg^(2+)diffusion paths from"hollow site→hollow site"to"hollow site→Se atom site→hollow site",largely decreasing the energy barrier and improving the Mg^(2+)diffusion kinetics.The present work highlights an efficient strategy for the improvement of Mg-storage performance for RMB cathodes.展开更多
Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combine...Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation(n-γ LDR).Methods: Fifty male Sprague-Dawley(SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20mg/(kg·d) cimetidine group, 80mg/(kg·d) cimetidine group and 160mg/(kg·d) cimetidine group(10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons(^(252)Cf, 0.085 m Gy/h) for 22 h every day and γ-rays(^(60)Co, 0.097Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to ^(252)Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A(Con A)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes(f MNPCEs), superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione peroxidase(GSH-Px) in the serum and liver tissues were detected.Results: The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26 th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly.Conclusions: The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.展开更多
The purpose of this study is to increase acrolein yield and capability of coking resistance in the reaction of glycerol dehydration to acrolein by assembling metal phosphate supported on HZSM-5 catalyst. The as-prepar...The purpose of this study is to increase acrolein yield and capability of coking resistance in the reaction of glycerol dehydration to acrolein by assembling metal phosphate supported on HZSM-5 catalyst. The as-prepared catalysts were characterized by XRD, SEM, EDS, BET, NH_3-TPD, CO_2-TPD and Py-IR techniques. It was found that metal phosphate species were incorporated into the porous structure of HZSM-5 zeolites, thus influencing the surface and textural physico-chemical properties of the supporters. The alkaline-treated HZSM-5 catalyst promoted the dispersion of phosphate species on the carriers. Moreover, the amount of strong acidity was tremendously improved by adding the different metal hydrophosphates and the catalysts show high catalytic activity. In this present work, the Sn1/4 H_2PO_4/HZSM-5 catalyst exhibited good performance in the catalytic activity and coking resistant ability, which resulted in a high acrolein yield of 83% initially and acrolein yield of 68% after 30 h. The acidity, especially the ratio of strong to weak acid, plays an important role in promoting acrolein yield and stability simultaneously.展开更多
Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement r...Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement resulting from the factors of wind, temperature, and gravity, among which the effect of gravity is especially pronounced. In this work, a three-dimensional laser scanner was employed to measure the main reflector and subreflector gravitational deformation of the Tianjin 70 m antenna at different elevation angles. Here, we solved the antenna main reflector deformation and sub-reflector displacement, and analyzed the deformation law of the antenna under the action of gravity. A new measurement method of antenna main reflector deformation and subreflector displacement is realized by mutual verification of the measured results and theoretical simulations. This method will help to improve the antenna performance and provide a reference to optimize the design of largeaperture antennas.展开更多
Foxtail millet(FM)whole grain has received special attention in recent years.To confirm the hypoglycemic effects of FM,we investigated the effects of FM supplementation on glucose metabolism and gut microbiota in rats...Foxtail millet(FM)whole grain has received special attention in recent years.To confirm the hypoglycemic effects of FM,we investigated the effects of FM supplementation on glucose metabolism and gut microbiota in rats with high-fat diet/streptozotocin(HFD/STZ)-induced diabetes.Specifically,we fully assessed the blood biochemical profiles,pancreatic histopathology,insulin-glucagon immunofluorescence,short-chain fatty acids,and gut microbiota composition of rats with HFD/STZ-induced diabetes before and after FM supplementation.Results showed that both 30% and 48% FM supplementation significantly decreased concentrations of fasting blood glucose,60-min blood glucose,and blood triglycerides(P<0.05);additionally,48% FM supplementation significantly improved blood glucose tolerance and insulin resistance(P<0.05).However,FM supplementation could not effectively repair damage to β-cells over a short period of time.In addition,4 weeks of 48% FM supplementation siginificantly increased the relative abundance of Bifidobacterium and concentration of butyrate,suggesting that the hypoglycemic effects of FM supplementation might be partially mediated by gut microbiota.Collectively,we found a dose-dependent relationship between FM supplementation and improvement of blood glucose metabolism,but did not find a synergistic effect between FM supplementation and metformin(Met)treatment.Our findings provide further support that consuming more whole-grain FM might be beneficial to individuals suffering from type 2 diabetes.展开更多
Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surfa...Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4km^4km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration.展开更多
基金funded by the National Natural Science Foundation of China(32101876)the Discipline ConstructionFood Science and Engineering(SPKX-202202)grants。
文摘Highland barley(HB)is a high-altitude cereal with rich nutritional components and potential health benefits.To clarify its hypoglycemic effect and mechanism,we investigated the effect of whole grain HB and fecal microbiota transplantation(FMT)on glucose metabolism and gut microbiota in high-fat diet and streptozotocin(HFD/STZ)-induced diabetic mice.The results showed that HB(40%)significantly decreased fasting blood glucose and the area under the glucose tolerance curve,significantly increased insulin secretion and improved insulin resistance in HFD/STZ-induced diabetic mice(P<0.05).Inflammatory factors and blood lipid indices were also significantly alleviated after 12 weeks of 40%HB intervention(P<0.05).Additionally,beneficial bacteria,such as Bifidobacterium and Akkermansia,were significantly enriched in the gut of diabetic mice after whole grain HB intervention.Meanwhile,the results of further FMT experiments verified that the fecal microbiota after the 40%HB intervention not only significantly increased the relative abundance of Bifidobacterium and Akkermansia but also effectively improved glucose metabolism and alleviated the inflammatory state in HFD/STZ-induced diabetic mice.Collectively,our study confirmed the bridge role of gut microbiota in improving glucose metabolism of whole grain HB,which could promote the development of precision nutrition.
基金This study was supported by the National Natural Science Foundation of China (21701182,51822208,21771187,21790050,and 21790051)the Frontier Science Research Project (QYZDB-SSW-JSC052)+1 种基金the Chinese Academy of Sciences,the Taishan Scholars Program of Shandong Province (tsqn201812111)Institute Research Project (QIBEBT ZZBS 201809).
文摘Carbyne delivers various excellent properties for the existence of the larger number of sp-hybridized carbon atoms.Here,a 3D well-defined porous carbon material germanium-carbdiyne(Ge-CDY)which is comprised of only sp-hybridized carbon atoms bridging by Ge atoms has been developed and investigated.The unique diamond-like structure constructed by linear butadiyne bonds and sp 3-hybridized Ge atoms ensures the stability of Ge-CDY.The large percentage of conjugated alkyne bonds composed of sp-C guarantees the good conductivity and the low band gap,which were further confirmed experimentally and theoretically,endowing Ge-CDY with the potential in electrochemical applications.The well-defined 3D carbon skeleton of Ge-CDY provides abundant uniform nanopores,which is suitable for metal ions storage and diffusion.Further half-cell evaluation also demonstrated Ge-CDY exhibited an excellent performance in lithium storage.All those indicating sp-hybridized carbon-based materials can exhibit great potential to possess excellent properties and be applied in the field of energy,electronic,and so on.
文摘A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this paper,the stress analysis of the main cable is carried out,and the relationship between the slope change and the coordinate change is found.This paper also discussed how to find the minimum slope point of symmetrical or asymmetric main cable,and the deformation compatibility equation is established and solved to obtain the shape of main cable.The algorithm in this paper can ensure the convergence of the solution for the suspension bridge with spatial cables.The calculation accuracy is high through the demonstration of the calculation examples.
基金supported by the Key Research Program of the Chinese Academy of Sciences(Grant No.ZDBS-SSW-TLC001)the National Natural Science Foundation(Grant No.11803056).
文摘China’s first Mars exploration mission,Tianwen-1,successfully landed in southern Utopia Planitia on Mars on May 15,2021.This work presents a detailed investigation of the geologic context of the landing area surface for this mission based on orbital remotesensing data.We constructed a geomorphologic map for the Tianwen-1 landing area.Results of our detailed geomorphologic map show several major landforms within the landing area,including rampart craters,mesas,troughs,cones,and ridges.Analysis of materials on the landing area surface indicates that most of the landing area is covered by Martian dust.Transverse aeolian ridges are widely distributed within the landing area,indicating the surface contexts were(and still are)modified by regional winds.In addition,a crater counting analysis indicates the landing area has an absolute model age of~3.3 Ga and that a later resurfacing event occurred at~1.6 Ga.Finally,we outline four formational scenarios to test the formation mechanisms for the geomorphologic features on the landing area surface.The most likely interpretation to explain the existence of the observed surface features can be summarized as follows:A thermal influence may have played an important role in the formation of the surface geomorphologic features;thus,igneous-related processes may have occurred in the landing area.Water ice may also have been involved in the construction of the primordial surface configuration.Subsequent resurfacing events and aeolian processes buried and modified the primordial surface.
文摘The Chang’E-6 mission will first land on the far side of the moon and bring lunar samples back.As a hyperspectral imager aboard the Chang’E-6 lander,the Lunar Mineralogical Spectrometer(LMS),will achieve the goal of spectral detection and mineral composition analysis in the sampling area,and the data of LMS will also be compared with the results of the returned sample laboratory measurements.Visible and near-infrared hyperspectral remote sensing is an effective tool for lunar minerals identification and quantification.The ground validation experiment can be used to evaluate the detection ability of the LMS.According to the modal abundances of lunar minerals and glasses of APOLLO samples,binary mixed samples,ternary mixed samples,and seven-membered mixed samples were prepared.The samples were ground and stirred homogeneous to about 200 mesh(median particle size about 75μm),to simulate the soil state of the lunar surface.Under the laboratory ambient condition,the 480–3200 nm spectral data of the samples were acquired using the Engineering Qualification Model(EQM)of Chang’E-5 LMS,the performance of which is consistent with the flight model of Chang’E-6 LMS.By fitting the mixed samples’spectral data of the EQM using the Modified Gaussian Methods,the following conclusions can be drawn:The subtle spectral changes of mixed samples can be detected.The modal abundance of low-Ca pyroxene,high-Ca pyroxene,and plagioclase can be derived based on the spectral parameters such as absorption position,depth or width of the mixed samples,and the correlation coefficients R2are better than 82%,indicating that the LMS has good quantitative detection capability.
基金supported by Intergovernmental International Science and Technology Innovation Cooperation Project(2019YFE0100200)National Natural Science Foundation of China(22179101 and 52172266).
文摘Rechargeable Mg batteries(RMBs)are a promising large-scale energy-storage technology with low cost and high safety,but the performance is limited by the inferior kinetics of Mg-intercalation cathodes.In the present study,an octylamine-supporting interlayer expanded molybdenum diselenide(e-MoSe_(2))is synthesized and used as cathode for RMBs,in comparison with ordinary crystalline MoSe_(2).The octylamine molecules introduced show a strong interaction with the MoSe_(2)layers and increase the layer spacing significantly from 6.46 to 11.5Å.e-MoSe_(2)shows a high Mg-storage capacity of 238 mAh g^(-1)at 50 mA g^(-1)and a superior rate performance of 39 mAh g^(-1)at 10 A g1,far advantageous over crystalline MoSe_(2).e-MoSe_(2)also shows a considerably high structure stability during repeated magnesiation/demagnesiation,providing an outstanding cycling stability for 1000 cycles.Further electrochemical tests demonstrate the high Mg^(2+)diffusion coefficients in e-MoSe_(2).Theoretical computation indicates the interlayer expansion changes the Mg^(2+)diffusion paths from"hollow site→hollow site"to"hollow site→Se atom site→hollow site",largely decreasing the energy barrier and improving the Mg^(2+)diffusion kinetics.The present work highlights an efficient strategy for the improvement of Mg-storage performance for RMB cathodes.
基金supported by the Research Fund of National Science and Technology Major Project of China(No.2014ZX09J14103-07B)
文摘Background: Cimetidine, an antagonist of histamine type II receptors, has shown protective effects against γ-rays or neutrons. However, there have been no reports on the effects of cimetidine against neutrons combined with γ-rays. This study was carried out to evaluate the protective effects of cimetidine on rats exposed to long-term, low-dose-rate neutron and γ-ray combined irradiation(n-γ LDR).Methods: Fifty male Sprague-Dawley(SD) rats were randomly divided into 5 groups: the normal control group, radiation model group, 20mg/(kg·d) cimetidine group, 80mg/(kg·d) cimetidine group and 160mg/(kg·d) cimetidine group(10 rats per group). Except for the normal control group, 40 rats were simultaneously exposed to fission neutrons(^(252)Cf, 0.085 m Gy/h) for 22 h every day and γ-rays(^(60)Co, 0.097Gy/h) for 1.03 h once every three days, and the cimetidine groups were administered intragastrically with cimetidine at doses of 20, 80 and 160mg/kg each day. Peripheral blood WBC of the rats was counted the day following exposure to γ-rays. The rats were anesthetized and sacrificed on the day following exposure to ^(252)Cf for 28 days. The spleen, thymus, testicle, liver and intestinal tract indexes were evaluated. The DNA content of bone marrow cells and concanavalin A(Con A)-induced lymphocyte proliferation were measured. The frequency of micronuclei in polychromatic erythrocytes(f MNPCEs), superoxide dismutase(SOD), malondialdehyde(MDA), and glutathione peroxidase(GSH-Px) in the serum and liver tissues were detected.Results: The peripheral blood WBC in the cimetidine groups was increased significantly on the 8th day and the 26 th day compared with those in the radiation model group. The spleen, thymus and testicle indexes of the cimetidine groups were higher than those of the radiation model group. The DNA content of bone marrow cells and lymphocyte proliferation in the cimetidine groups were increased significantly, and fMNPCE was reduced 1.41-1.77 fold in cimetidine treated groups. The activities of SOD and GSH-Px in the cimetidine groups were increased significantly, and the content of MDA in the cimetidine groups was decreased significantly.Conclusions: The results suggested that cimetidine alleviated damage induced by long-term, low-dose-rate neutron and γ combined irradiation via antioxidation and immunomodulation. Cimetidine might be useful as a potent radioprotector for radiotherapy patients as well as for occupational exposure workers.
基金Supported by the National Natural Science Foundation of China(21676288)
文摘The purpose of this study is to increase acrolein yield and capability of coking resistance in the reaction of glycerol dehydration to acrolein by assembling metal phosphate supported on HZSM-5 catalyst. The as-prepared catalysts were characterized by XRD, SEM, EDS, BET, NH_3-TPD, CO_2-TPD and Py-IR techniques. It was found that metal phosphate species were incorporated into the porous structure of HZSM-5 zeolites, thus influencing the surface and textural physico-chemical properties of the supporters. The alkaline-treated HZSM-5 catalyst promoted the dispersion of phosphate species on the carriers. Moreover, the amount of strong acidity was tremendously improved by adding the different metal hydrophosphates and the catalysts show high catalytic activity. In this present work, the Sn1/4 H_2PO_4/HZSM-5 catalyst exhibited good performance in the catalytic activity and coking resistant ability, which resulted in a high acrolein yield of 83% initially and acrolein yield of 68% after 30 h. The acidity, especially the ratio of strong to weak acid, plays an important role in promoting acrolein yield and stability simultaneously.
基金funded by the Key Research Program of the Chinese Academy of Science (ZDBS-SSW-TLC001)。
文摘Large antennas play an important role in deep space exploration and astronomical research. However, their performances are inevitably affected by the main reflector surface deformation and sub-reflector displacement resulting from the factors of wind, temperature, and gravity, among which the effect of gravity is especially pronounced. In this work, a three-dimensional laser scanner was employed to measure the main reflector and subreflector gravitational deformation of the Tianjin 70 m antenna at different elevation angles. Here, we solved the antenna main reflector deformation and sub-reflector displacement, and analyzed the deformation law of the antenna under the action of gravity. A new measurement method of antenna main reflector deformation and subreflector displacement is realized by mutual verification of the measured results and theoretical simulations. This method will help to improve the antenna performance and provide a reference to optimize the design of largeaperture antennas.
基金supported by the National Key R&D Program of China(2017YFD0401200)China Agriculture Research System(CARS-07-13.5-A17)+1 种基金General S&T project of Beijing Municipal Commission of Education(KM202010011006)BTBU Youth Fund(PXM2019_014213_000007).
文摘Foxtail millet(FM)whole grain has received special attention in recent years.To confirm the hypoglycemic effects of FM,we investigated the effects of FM supplementation on glucose metabolism and gut microbiota in rats with high-fat diet/streptozotocin(HFD/STZ)-induced diabetes.Specifically,we fully assessed the blood biochemical profiles,pancreatic histopathology,insulin-glucagon immunofluorescence,short-chain fatty acids,and gut microbiota composition of rats with HFD/STZ-induced diabetes before and after FM supplementation.Results showed that both 30% and 48% FM supplementation significantly decreased concentrations of fasting blood glucose,60-min blood glucose,and blood triglycerides(P<0.05);additionally,48% FM supplementation significantly improved blood glucose tolerance and insulin resistance(P<0.05).However,FM supplementation could not effectively repair damage to β-cells over a short period of time.In addition,4 weeks of 48% FM supplementation siginificantly increased the relative abundance of Bifidobacterium and concentration of butyrate,suggesting that the hypoglycemic effects of FM supplementation might be partially mediated by gut microbiota.Collectively,we found a dose-dependent relationship between FM supplementation and improvement of blood glucose metabolism,but did not find a synergistic effect between FM supplementation and metformin(Met)treatment.Our findings provide further support that consuming more whole-grain FM might be beneficial to individuals suffering from type 2 diabetes.
基金Supported by the National Natural Science Foundation of China
文摘Chang'e-3 (CE-3) landed on the Mare Imbrium basin in the east part of Sinus Iridum (19.51°W, 44.12°N), which was China's first soft landing on the Moon and it started collecting data on the lunar surface environment. To better understand the environment of this region, this paper utilizes the available high-resolution topography data, image data and geological data to carry out a detailed analysis and research on the area surrounding the landing site (Sinus Iridum and 45 km×70 km of the landing area) as well as on the topography, landform, geology and lunar dust of the area surrounding the landing site. A general topographic analysis of the surrounding area is based on a digital elevation model and digital elevation model data acquired by Chang'e-2 that have high resolution; the geology analysis is based on lunar geological data published by USGS; the study on topographic factors and distribution of craters and rocks in the surrounding area covering 4km^4km or even smaller is based on images from the CE-3 landing camera and images from the topographic camera; an analysis is done of the effect of the CE-3 engine plume on the lunar surface by comparing images before and after the landing using data from the landing camera. A comprehensive analysis of the results shows that the landing site and its surrounding area are identified as typical lunar mare with flat topography. They are suitable for maneuvers by the rover, and are rich in geological phenomena and scientific targets, making it an ideal site for exploration.