As the nation opens its arms to commemorate the 60th anniversary of i the People’s Republic of China on lOctober 1, historic items spanning the past decades are changing hands with a fer-
The effects of the heating process and hot extrusion on the microstructure and properties of inconel 625 alloy were studied. The experimental results showed that the properties of Inconel 625 alloy could be improved t...The effects of the heating process and hot extrusion on the microstructure and properties of inconel 625 alloy were studied. The experimental results showed that the properties of Inconel 625 alloy could be improved through the heating process and hot extrusion concomitant with a reduced corrosion rate. The M23C6 carbide, generated in the heating process, was retained and distributed at the grain boundary during the process of hot extrusion, which had an important influence on both elongation and corrosion resistance. The improvement of the comprehensive properties of the material, as measured by a tensile test at room temperature, was correlated with the dissolution of segregation Nb. A typical ductile fracture changed to a cleavage fracture where secondary cracks could be clearly seen. With the increase of the extrusion ratio, the real extrusion temperature was higher, which led to more dissolution of the M23C6 carbide, decreased the number of secondary cracks, enhanced the effect of solid solution strengthening, and reduced the intergranular corrosion rate. Under the condition of a high extrusion ratio and a high extrusion speed, the less extrusion time made it possible to obtain organization with a smaller average grain size. Moreover, in this case, the M23C6 carbide and segregated Nb did not have enough time to diffuse. Thus all samples exhibited medium strengths and corrosion rates after extrusion.展开更多
The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure a...The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure and improved mechanical properties of the A356 aluminum alloy. During the hot spinning process, eutectic Si particles and Fe-rich phases were fragmented, and porosities were eliminated. In addition, recrystallization of Al matrix and precipitation of Al Si Ti phases occurred. The mechanical property testing results indicated that there was a significant increase of ductility and a decrease of average microhardness in deformed alloy over die-cast alloy. This is attributed to uniform distribution of finer spherical eutectic Si particles, the elimination of casting defects and to the recrystallized finer grain structure.展开更多
Three different online heat treatment processes were designed to study the effects on the mechanical properties of a 0.19C-1.6Si-1.6Mn(wt%) hot rolled strip steel.The microstructures were characterized by means of S...Three different online heat treatment processes were designed to study the effects on the mechanical properties of a 0.19C-1.6Si-1.6Mn(wt%) hot rolled strip steel.The microstructures were characterized by means of SEM,TEM,EPMA,and XRD.The mechanical properties were estimated by tensile tests.Results showed that a satisfying combination of strength and ductility could be obtained through the ferrite relaxation and direct quenching and partitioning process.Analysis was also focused on this process.The microstructure contained proeutectoid ferrite grains,martensite packets and blocky or interlath retained austenite,and also contained carbide-free bainite in the case of relatively high quench temperatures.The retained austenite fraction was increased through proeutectoid ferrite and partial bainite transformation,while the tensile strength was also consequently decreased.The most of retained austenite transformed to ferrite under deformation and the elongation was obviously improved.展开更多
The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, a...The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.展开更多
Calcium aluminate cement(CAC)bonded corundum based castables were prepared using tabular corundum and activated alumina as the starting materials,CAC as the binder,zinc hydroxide(Zn(OH)_(2))and basic zinc carbonate(BZ...Calcium aluminate cement(CAC)bonded corundum based castables were prepared using tabular corundum and activated alumina as the starting materials,CAC as the binder,zinc hydroxide(Zn(OH)_(2))and basic zinc carbonate(BZC)as the ZnO precursors.The effects of the two ZnO precursors on the phase composition and the microstructure of the CAC bonded corundum based castable matrix specimens were analyzed,and the reasons affecting the hot performance of the castables were studied.The results show that Zn(OH)_(2) with a smaller particle size(d_(50)=1.26μm)is prone to agglomerate during sample preparation and generates ZnAl_(2)O_(4) spinel grains after firing,hindering the growth of CA_(6),thus decreasing the mechanical strength of the castables.BZC with a larger particle size(d_(50)=2.91μm),which shows a sound dispersity,in-situ generates nano-sized ZnO after firing,and ZnO or Zn^(2+)diffuses into calcium aluminates,promoting the sintering of CA_(2) and CA_(6),thereby enhancing the hot properties of the CAC-bonded corundum based castables.展开更多
Objective: To determine the hot/cold of South American A?aí(Euterpe oleracea Mart.). Materials and Methods: 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay was performed to compare the in...Objective: To determine the hot/cold of South American A?aí(Euterpe oleracea Mart.). Materials and Methods: 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay was performed to compare the influence of A?aí and phellodendron bark(Cortex Phellodendri Chinensis) on the growth and proliferation of HepG2 and Hep3 B cell strains. The morphological changes of the two cell strains treated with A?aí and C. Phellodendri were observed using an inverted phase contrast microscope. Trypan blue dye exclusion assay was used to compare and analyze the toxicity effects of A?aí. The content of nicotinamide adenine dinucleotide(NADH) and the ratio of NADH/NAD+ of the treated cells were detected using a spectrophotometer to determine the influence of A?aí to the energy metabolism of the two cell strains. Results: Within the range of measured concentrations, both A?aí and C. Phellodendri displayed separately the stronger inhibitory effects on cell growth, proliferation, and energy metabolism of the two cell strains. By MTT assay, A?aí showed significant(P < 0.05) or highly significant(P < 0.01) inhibitory effects on cell proliferation within the concentration range of 0.25–40 μg/mL, which was similar to the effects of C. Phellodendri. From the results of microscopic examination, the morphological of lower cell density, attenuated granularity, and more outstretched cells in irregular polygonal shape could be observed in the cells treated with A?aí, which was also similar to that of C. Phellodendri. In trypan blue staining assay, all concentrations of A?aí showed negligible toxicity effects, exactly as that of C. Phellodendri. A?aí showed a highly significant effect of decreasing the content of intracellular NADH as well as the ratio of NADH/NAD+(P < 0.05 and P < 0.01, respectively). Conclusion: The effect of A?aí on HepG2 and Hep3 B strains just as C. Phellodendri can reduce energy metabolism and inhibit the growth and proliferation. All performance characteristics of two cell strains treated with A?aí belong to that characteristic of cold property drug. From the study results, we can deduce that the drug property of A?aí is cold.展开更多
It recently becomes an important and urgent mission for modern scientific research to identify and explain the theory of traditional Chinese medicine(TCM), which has been utilized in China for more than four millennia...It recently becomes an important and urgent mission for modern scientific research to identify and explain the theory of traditional Chinese medicine(TCM), which has been utilized in China for more than four millennia. Since few works have been contributed to understanding the TCM theory, the mechanism of actions of drugs with cold/hot properties remains unclear. In the present study, six kinds of typical herbs with cold or hot properties were orally administered into mice, and serum and liver samples were analyzed using an untargeted nuclear magnetic resonance(NMR) based metabolomics approach coupled with similarity analysis. This approach was performed to identify and quantify changes in metabolic pathways to elucidate drug actions on the treated mice. Our results showed that those drugs with same property exerted similar effects on the metabolic alterations in mouse serum and liver samples, while drugs with different property showed different effects. The effects of herbal medicines with cold/hot properties were exerted by regulating the pathways linked to glycometabolism, lipid metabolism, amino acids metabolism and other metabolic pathways. The results elucidated the differences and similarities of drugs with cold/hot properties, providing useful information on the explanation of medicinal properties of these TCMs.展开更多
In this study, the influence of hot isostatic pressing(HIP) process on the 418 alloy produced by metal injection molding(MIM) technique(named as MIM 418)was investigated based on the characteristic analysis of 4...In this study, the influence of hot isostatic pressing(HIP) process on the 418 alloy produced by metal injection molding(MIM) technique(named as MIM 418)was investigated based on the characteristic analysis of 418 alloy powder. And comparison analysis of the microstructure and mechanical property between the MIM 418 and as-cast 418 alloys was performed by scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD). The results show that MIM418 alloy exhibits fine grain(~30 μm) and uniform microstructure. The defects existing in MIM 418 alloy formed during sintering process can be eliminated through HIP treatment, and the relative density increases from97.0 % to 99.5 %. The mechanical property can be improved significantly because of the elimination of defects, and the tensile strength and elongation are1,271 MPa and 16.8 %, respectively, which are increased by 34.5 % and 180 % compared with K418 alloy after solution heat treatment.展开更多
Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals ...Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly(propylene carbonate)(PPC) is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive(RHMPA) based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics(PC, PMMA, ABS) and metals(aluminium, steel), which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process(up to 270 °C). The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.展开更多
Bitumen requirement in hot mix asphalt (HMA) is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface a...Bitumen requirement in hot mix asphalt (HMA) is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established ]aboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.展开更多
Objective: To study the influence of Radix aconiti lateralis preparata and Rhizoma zingiberis, two species of Chinese medicinal herbs with hot property, on energy metabolism and gene expression spectrum, and to analy...Objective: To study the influence of Radix aconiti lateralis preparata and Rhizoma zingiberis, two species of Chinese medicinal herbs with hot property, on energy metabolism and gene expression spectrum, and to analyze the possible mechanism of their effects. Methods: Forty-eight specific pathogen free Wistar rats were randomly divided into a Radix aconiti lateralis preparata group, a Rhizoma zingiberis group, and a control group. They were intragastrically treated with concentrated decoction of Radix aconiti lateralis preparata, Rhizoma zingiberis and normal saline respectively for 20 days. Toe temperature (TT), energy intake (El), digestible energy (DE), and metabolizable energy (ME) were measured. The content of adenosine triphosphate (ATP) and energy charge (EC) in hepatic tissue were measured with high performance liquid chromatography (HPLC). The activity of ATPase and succinate dehydrogenase (SDH) in the liver were detected with chemical colorimetry. The gene expression in the liver was detected with Illumina's rat Ref-12 gene array. The differential expression genes were selected, annotated and classified based on Gene Ontology (GO). Real-time quantitative reverse-transcriptase PCR (Q-RT-PCR) was used to test the accuracy of results. Results: Compared with the control group, the -I-r on the 10^th day after the beginning of administration and ATP in the Radix aconiti lateralis preparata and Rhizoma zingiberis groups increased significantly (P〈0.05). El/body mass (BM), DE/BM, ME/BM, the hepatic EC and the activity of Na^+-K^+-ATPase, Ca^2+-Mg^2+-ATPase and SDH of liver increased significantly only in the Radix aconiti lateralis preparata group (P〈0.05). There were 592 differential expression genes in the Radix aconiti/ateralis preparata group and 1 159 in the Rhizoma zingiberis group compared with the control group. Among the differential expression genes, genes related to metabolic processes were the most significant based on GO analysis. There were 337 strips of gene differential expression in common in both Radix aconiti lateralis preparata and Rhizoma zingiberis groups compared with the control group. Conclusions: Herbs with hot property such as Radix aconiti lateralis preparata and Rhizoma zingiberis could improve the energy metabolism in rats, through influencing the metabolic process of sugar, lipid, and amino acid. It could also promote the production, storage, and utilization of energy by regulating the gene expression related to metabolism, which may be the main molecular mechanism of warming yang and dispelling cold for the treatment of the cold syndrome according to Chinese medicine theory.展开更多
A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work ...A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work theoretically explores the role of the surface energy coefficient and energy-dependent nucleus-nucleus proxim-ity potential in the mechanism of the fusion hindrance of 14 typical colliding systems with negative Q-values,in-eluding ^(11a)B+^(197)AU,^(12)C+^(198)Pt,^(16)O+^(208)Pb,^(28)Si+^(94Mo),^(48)Ca+^(96)Zr,^(28Si+)^(64)Ni,^(58)Ni+^(58)Ni+,^(60)Ni+^(89)Y,^(12)C+^(204)Pb,^(36)S+^(64)Ni,^(36)S+^(90)Zr,^(40)Ca+^(90)Zr,^(40)Ca+^(40Ca)and ^(48)Ca+^(48)Ca,,as well as five typical colliding systems with positive Q-values,ineluding ^(12)C+^(30)Si,^24Mg+^(30)Si,^(36)Si+^(48)Ca, and ^(40)Ca+^(48)Ca.It is shown that the outcomes based on the proximity potential along with the above-mentioned physical effects achieve reasonable agreement with the experimentally observed data of the fusion cross sections(Tfus(£),astrophysical S(E)factors,and logarithmic derivatives L(E)in the energy region far below the Coulomb barrier.A discussion is also presented on the performance of the present theoretical approach in reproducing the experimental fusion barrier distributions for different colliding systems.展开更多
文摘As the nation opens its arms to commemorate the 60th anniversary of i the People’s Republic of China on lOctober 1, historic items spanning the past decades are changing hands with a fer-
基金Funded by the National Natural Science Foundation of China(Nos.51664041 and 51365029)the Gansu Science and Technology Support Program-industrial Category(No.1604GKCA038)+1 种基金the Fundamental Research Funds for the Universities in Gansu Provincethe Program for Major Projects of Science and Technology in Gansu Province(No.145RTSA004)
文摘The effects of the heating process and hot extrusion on the microstructure and properties of inconel 625 alloy were studied. The experimental results showed that the properties of Inconel 625 alloy could be improved through the heating process and hot extrusion concomitant with a reduced corrosion rate. The M23C6 carbide, generated in the heating process, was retained and distributed at the grain boundary during the process of hot extrusion, which had an important influence on both elongation and corrosion resistance. The improvement of the comprehensive properties of the material, as measured by a tensile test at room temperature, was correlated with the dissolution of segregation Nb. A typical ductile fracture changed to a cleavage fracture where secondary cracks could be clearly seen. With the increase of the extrusion ratio, the real extrusion temperature was higher, which led to more dissolution of the M23C6 carbide, decreased the number of secondary cracks, enhanced the effect of solid solution strengthening, and reduced the intergranular corrosion rate. Under the condition of a high extrusion ratio and a high extrusion speed, the less extrusion time made it possible to obtain organization with a smaller average grain size. Moreover, in this case, the M23C6 carbide and segregated Nb did not have enough time to diffuse. Thus all samples exhibited medium strengths and corrosion rates after extrusion.
基金supported by the National Key Research Project(No.2016YFB0300901)
文摘The evolution of microstructure and mechanical properties of A356 aluminum alloy subjected to hot spinning process has been investigated. The results indicated that the deformation process homogenized microstructure and improved mechanical properties of the A356 aluminum alloy. During the hot spinning process, eutectic Si particles and Fe-rich phases were fragmented, and porosities were eliminated. In addition, recrystallization of Al matrix and precipitation of Al Si Ti phases occurred. The mechanical property testing results indicated that there was a significant increase of ductility and a decrease of average microhardness in deformed alloy over die-cast alloy. This is attributed to uniform distribution of finer spherical eutectic Si particles, the elimination of casting defects and to the recrystallized finer grain structure.
基金Funded by the National Basic Research Program of China(No.51504063)the Natural Science Foundation of Liaoning Province of China(No.2014020027)the Fundamental Research Funds for the Central Universities(No.N130407001)
文摘Three different online heat treatment processes were designed to study the effects on the mechanical properties of a 0.19C-1.6Si-1.6Mn(wt%) hot rolled strip steel.The microstructures were characterized by means of SEM,TEM,EPMA,and XRD.The mechanical properties were estimated by tensile tests.Results showed that a satisfying combination of strength and ductility could be obtained through the ferrite relaxation and direct quenching and partitioning process.Analysis was also focused on this process.The microstructure contained proeutectoid ferrite grains,martensite packets and blocky or interlath retained austenite,and also contained carbide-free bainite in the case of relatively high quench temperatures.The retained austenite fraction was increased through proeutectoid ferrite and partial bainite transformation,while the tensile strength was also consequently decreased.The most of retained austenite transformed to ferrite under deformation and the elongation was obviously improved.
文摘The basic formulation of Al2O3- C slide plates was65%( in mass,the same hereinafter) white fused corundum particles,25% white fused corundum fines,6% active α-Al2O3 micropowder,4% carbon black and flake graphite, and additional 4% phenolic resin.Based on this formulation,3% Al powder,3% Si powder,and 3% Al + 3% Si powder were used to substitute equivalent white corundum fines to improve the hot mechanical properties of Al2O3- C slide plates. The specimens with dimensions of 140 mm × 25 mm × 25 mm were pressed at 150 MPa,dried at 200 ℃ for 24 h,and hot treated at 1 400 ℃ for 3 h in carbon embedded condition. Then hot modulus of rupture and thermal shock resistance of the specimens were tested and the phase compositions and microstructure were analyzed. The results show that specimen with 3% Al powder has the higher hot modulus of rupture but lower residual modulus of rupture after thermal shock than the specimen with3% Si powder; the specimen with 3% Al + 3% Si powders exhibits the highest hot modulus of rupture and the best thermal shock resistance; the change of mechanical property is closely related with the in-situ formed nonoxides: AlN in the form of bars is formed in specimens with Al powder; fibrous SiC whiskers are formed in specimens with Si powder; in the specimens with both Al and Sipowders,besides AlN and SiC whiskers,hexagonal tabular SiAlON is in-situ synthesized,which interlocks with each other.
文摘Calcium aluminate cement(CAC)bonded corundum based castables were prepared using tabular corundum and activated alumina as the starting materials,CAC as the binder,zinc hydroxide(Zn(OH)_(2))and basic zinc carbonate(BZC)as the ZnO precursors.The effects of the two ZnO precursors on the phase composition and the microstructure of the CAC bonded corundum based castable matrix specimens were analyzed,and the reasons affecting the hot performance of the castables were studied.The results show that Zn(OH)_(2) with a smaller particle size(d_(50)=1.26μm)is prone to agglomerate during sample preparation and generates ZnAl_(2)O_(4) spinel grains after firing,hindering the growth of CA_(6),thus decreasing the mechanical strength of the castables.BZC with a larger particle size(d_(50)=2.91μm),which shows a sound dispersity,in-situ generates nano-sized ZnO after firing,and ZnO or Zn^(2+)diffuses into calcium aluminates,promoting the sintering of CA_(2) and CA_(6),thereby enhancing the hot properties of the CAC-bonded corundum based castables.
基金supported by grants from the Science and Technology Plan Project of Guangdong Province(Grant No.2014A070713031,2015A020209134)Science and Technology Plan Project of Guangzhou(Grant No.201604020171)
文摘Objective: To determine the hot/cold of South American A?aí(Euterpe oleracea Mart.). Materials and Methods: 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide(MTT) assay was performed to compare the influence of A?aí and phellodendron bark(Cortex Phellodendri Chinensis) on the growth and proliferation of HepG2 and Hep3 B cell strains. The morphological changes of the two cell strains treated with A?aí and C. Phellodendri were observed using an inverted phase contrast microscope. Trypan blue dye exclusion assay was used to compare and analyze the toxicity effects of A?aí. The content of nicotinamide adenine dinucleotide(NADH) and the ratio of NADH/NAD+ of the treated cells were detected using a spectrophotometer to determine the influence of A?aí to the energy metabolism of the two cell strains. Results: Within the range of measured concentrations, both A?aí and C. Phellodendri displayed separately the stronger inhibitory effects on cell growth, proliferation, and energy metabolism of the two cell strains. By MTT assay, A?aí showed significant(P < 0.05) or highly significant(P < 0.01) inhibitory effects on cell proliferation within the concentration range of 0.25–40 μg/mL, which was similar to the effects of C. Phellodendri. From the results of microscopic examination, the morphological of lower cell density, attenuated granularity, and more outstretched cells in irregular polygonal shape could be observed in the cells treated with A?aí, which was also similar to that of C. Phellodendri. In trypan blue staining assay, all concentrations of A?aí showed negligible toxicity effects, exactly as that of C. Phellodendri. A?aí showed a highly significant effect of decreasing the content of intracellular NADH as well as the ratio of NADH/NAD+(P < 0.05 and P < 0.01, respectively). Conclusion: The effect of A?aí on HepG2 and Hep3 B strains just as C. Phellodendri can reduce energy metabolism and inhibit the growth and proliferation. All performance characteristics of two cell strains treated with A?aí belong to that characteristic of cold property drug. From the study results, we can deduce that the drug property of A?aí is cold.
基金supported by the Science and Technology Innovation Team of Shanxi Province(No.2013131015)Program for the Outstanding Innovative Teams of Higher Learning Institutions of Shanxi(OIT)
文摘It recently becomes an important and urgent mission for modern scientific research to identify and explain the theory of traditional Chinese medicine(TCM), which has been utilized in China for more than four millennia. Since few works have been contributed to understanding the TCM theory, the mechanism of actions of drugs with cold/hot properties remains unclear. In the present study, six kinds of typical herbs with cold or hot properties were orally administered into mice, and serum and liver samples were analyzed using an untargeted nuclear magnetic resonance(NMR) based metabolomics approach coupled with similarity analysis. This approach was performed to identify and quantify changes in metabolic pathways to elucidate drug actions on the treated mice. Our results showed that those drugs with same property exerted similar effects on the metabolic alterations in mouse serum and liver samples, while drugs with different property showed different effects. The effects of herbal medicines with cold/hot properties were exerted by regulating the pathways linked to glycometabolism, lipid metabolism, amino acids metabolism and other metabolic pathways. The results elucidated the differences and similarities of drugs with cold/hot properties, providing useful information on the explanation of medicinal properties of these TCMs.
基金financially supported by the National High Technology Research and Development Program of China (No. 2012AA03AA514)
文摘In this study, the influence of hot isostatic pressing(HIP) process on the 418 alloy produced by metal injection molding(MIM) technique(named as MIM 418)was investigated based on the characteristic analysis of 418 alloy powder. And comparison analysis of the microstructure and mechanical property between the MIM 418 and as-cast 418 alloys was performed by scanning electron microscopy(SEM), energy-dispersive spectroscopy(EDS),and X-ray diffraction(XRD). The results show that MIM418 alloy exhibits fine grain(~30 μm) and uniform microstructure. The defects existing in MIM 418 alloy formed during sintering process can be eliminated through HIP treatment, and the relative density increases from97.0 % to 99.5 %. The mechanical property can be improved significantly because of the elimination of defects, and the tensile strength and elongation are1,271 MPa and 16.8 %, respectively, which are increased by 34.5 % and 180 % compared with K418 alloy after solution heat treatment.
基金financially supported by the National Natural Science Foundation of China(Nos.21574019 and 21304015)the Fundamental Research Funds for the Central Universities and the DHU Distinguished Young Professor Program(No.B201303)
文摘Tens of billion metric tons of anthropogenic CO_2 discharged from the burning of fossil fuels lead to an enormous environmental and resource burden. It is charming to transform CO_2 to desirable, economical chemicals and materials. Poly(propylene carbonate)(PPC) is an emerging CO_2-based material. Herein, we report the design, synthesis and characterization of the reactive hot melt polyurethane adhesive(RHMPA) based on PPC polyol. The resultant RHMPAs exhibit good adhesion properties to multiple substrates including plastics(PC, PMMA, ABS) and metals(aluminium, steel), which is comparable to or even better than conventional RHMPAs prepared from petro-based polyol. Furthermore, the PPC-based RHMPAs have tunable mechanical properties, and are thermally stable in the typical working range of bonding process(up to 270 °C). The study is expected to expand the applications of PPC and provide a new type of CO_2-based renewable and eco-friendly materials.
文摘Bitumen requirement in hot mix asphalt (HMA) is directly dependent on the surface area of the aggregates in the mix, which in turn has effect on the asphalt film thickness and the flow characteristics. The surface area of aggregate blend in HMA is calculated using the specific surface area factors assigned to percentage passing through some specific standard sieve sizes and the imaging techniques. The first process is less capital intensive, but purely manual and labour intensive and prone to human errors. Imaging techniques though eliminating the human errors, still have limited use due to capital intensiveness and requirement of well-established ]aboratories with qualified technicians. Most of the developing countries like India are shortage of well-equipped laboratories and qualified technicians. To overcome these difficulties, the present mathematical model has been developed to estimate the surface area of aggregate blend of HMA from physical properties of aggregates evaluated using simple laboratory equipment. This model has been validated compared with the existing established methods of calculations and can be used as one of the tools in different developing and under developed countries for proper design of HMA.
基金Supported by the National Basic Research Program of China (973 Program,No.2007CB512601)
文摘Objective: To study the influence of Radix aconiti lateralis preparata and Rhizoma zingiberis, two species of Chinese medicinal herbs with hot property, on energy metabolism and gene expression spectrum, and to analyze the possible mechanism of their effects. Methods: Forty-eight specific pathogen free Wistar rats were randomly divided into a Radix aconiti lateralis preparata group, a Rhizoma zingiberis group, and a control group. They were intragastrically treated with concentrated decoction of Radix aconiti lateralis preparata, Rhizoma zingiberis and normal saline respectively for 20 days. Toe temperature (TT), energy intake (El), digestible energy (DE), and metabolizable energy (ME) were measured. The content of adenosine triphosphate (ATP) and energy charge (EC) in hepatic tissue were measured with high performance liquid chromatography (HPLC). The activity of ATPase and succinate dehydrogenase (SDH) in the liver were detected with chemical colorimetry. The gene expression in the liver was detected with Illumina's rat Ref-12 gene array. The differential expression genes were selected, annotated and classified based on Gene Ontology (GO). Real-time quantitative reverse-transcriptase PCR (Q-RT-PCR) was used to test the accuracy of results. Results: Compared with the control group, the -I-r on the 10^th day after the beginning of administration and ATP in the Radix aconiti lateralis preparata and Rhizoma zingiberis groups increased significantly (P〈0.05). El/body mass (BM), DE/BM, ME/BM, the hepatic EC and the activity of Na^+-K^+-ATPase, Ca^2+-Mg^2+-ATPase and SDH of liver increased significantly only in the Radix aconiti lateralis preparata group (P〈0.05). There were 592 differential expression genes in the Radix aconiti/ateralis preparata group and 1 159 in the Rhizoma zingiberis group compared with the control group. Among the differential expression genes, genes related to metabolic processes were the most significant based on GO analysis. There were 337 strips of gene differential expression in common in both Radix aconiti lateralis preparata and Rhizoma zingiberis groups compared with the control group. Conclusions: Herbs with hot property such as Radix aconiti lateralis preparata and Rhizoma zingiberis could improve the energy metabolism in rats, through influencing the metabolic process of sugar, lipid, and amino acid. It could also promote the production, storage, and utilization of energy by regulating the gene expression related to metabolism, which may be the main molecular mechanism of warming yang and dispelling cold for the treatment of the cold syndrome according to Chinese medicine theory.
文摘A systematic survey of the accurate measurements of heavy-ion fusion cross sections at extreme sub-barrier energies is performed using the coupled-channels(CC)theory that is based on the proximity formalism.This work theoretically explores the role of the surface energy coefficient and energy-dependent nucleus-nucleus proxim-ity potential in the mechanism of the fusion hindrance of 14 typical colliding systems with negative Q-values,in-eluding ^(11a)B+^(197)AU,^(12)C+^(198)Pt,^(16)O+^(208)Pb,^(28)Si+^(94Mo),^(48)Ca+^(96)Zr,^(28Si+)^(64)Ni,^(58)Ni+^(58)Ni+,^(60)Ni+^(89)Y,^(12)C+^(204)Pb,^(36)S+^(64)Ni,^(36)S+^(90)Zr,^(40)Ca+^(90)Zr,^(40)Ca+^(40Ca)and ^(48)Ca+^(48)Ca,,as well as five typical colliding systems with positive Q-values,ineluding ^(12)C+^(30)Si,^24Mg+^(30)Si,^(36)Si+^(48)Ca, and ^(40)Ca+^(48)Ca.It is shown that the outcomes based on the proximity potential along with the above-mentioned physical effects achieve reasonable agreement with the experimentally observed data of the fusion cross sections(Tfus(£),astrophysical S(E)factors,and logarithmic derivatives L(E)in the energy region far below the Coulomb barrier.A discussion is also presented on the performance of the present theoretical approach in reproducing the experimental fusion barrier distributions for different colliding systems.