Objective To develop a model based on a graph convolutional network(GCN)to achieve ef-ficient classification of the cold and hot medicinal properties of Chinese herbal medicines(CHMs).Methods After screening the datas...Objective To develop a model based on a graph convolutional network(GCN)to achieve ef-ficient classification of the cold and hot medicinal properties of Chinese herbal medicines(CHMs).Methods After screening the dataset provided in the published literature,this study includ-ed 495 CHMs and their 8075 compounds.Three molecular descriptors were used to repre-sent the compounds:the molecular access system(MACCS),extended connectivity finger-print(ECFP),and two-dimensional(2D)molecular descriptors computed by the RDKit open-source toolkit(RDKit_2D).A homogeneous graph with CHMs as nodes was constructed and a classification model for the cold and hot medicinal properties of CHMs was developed based on a GCN using the molecular descriptor information of the compounds as node features.Fi-nally,using accuracy and F1 score to evaluate model performance,the GCN model was ex-perimentally compared with the traditional machine learning approaches,including decision tree(DT),random forest(RF),k-nearest neighbor(KNN),Naïve Bayes classifier(NBC),and support vector machine(SVM).MACCS,ECFP,and RDKit_2D molecular descriptors were al-so adopted as features for comparison.Results The experimental results show that the GCN achieved better performance than the traditional machine learning approach when using MACCS as features,with the accuracy and F1 score reaching 0.8364 and 0.8453,respectively.The accuracy and F1 score have increased by 0.8690 and 0.8120,respectively,compared with the lowest performing feature combina-tion OMER(only the combination of MACCS,ECFP,and RDKit_2D).The accuracy and F1 score of DT,RF,KNN,NBC,and SVM are 0.5051 and 0.5018,0.6162 and 0.6015,0.6768 and 0.6243,0.6162 and 0.6071,0.6364 and 0.6225,respectively.Conclusion In this study,by introducing molecular descriptors as features,it is verified that molecular descriptors and fingerprints play a key role in classifying the cold and hot medici-nal properties of CHMs.Meanwhile,excellent classification performance was achieved using the GCN model,providing an important algorithmic basis for the in-depth study of the“struc-ture-property”relationship of CHMs.展开更多
The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-do...The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.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
The high effective nano-hybrid pour point depressant(PPD)has attracted extensive attention for its po-tential application in improving the cold flow properties of diesel fuel.In this paper,the nano-hybrid PPD was prep...The high effective nano-hybrid pour point depressant(PPD)has attracted extensive attention for its po-tential application in improving the cold flow properties of diesel fuel.In this paper,the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths(i.e.,tetradecyl,hexade-cyl,and octodecyl)of n-alkyl methacrylate-maleic anhydride copolymers(R 1 MC-MA,R 1=C_(14),C_(16),C_(18))and SiO_(2)nanoparticles.The effect of those nano-hybrid PPDs on the cold filter plugging point(CFPP)and solidifying point(SP)depressing of diesel fuel were studied.Results indicated that nano-hybrid PPD showed much better performance on diesel fuel.The diesel fuel treated with 0.2 wt%C_(14)MC-MA/SiO_(2)nano-hybrid PPD exhibited the best depression in CFPP and SP by 6℃ and 18℃,respectively,which higher than that of single C 14 MC-MA.Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism;and results presented that nano-hybrid PPD of C_(14)MC-MA/SiO_(2)could effectively lower the low-temperature viscosity,and modify the crystallization behavior and crystal morphology of diesel.Therefore,the cold flow properties of diesel were significantly improved.展开更多
Six kinds of polyurethane （PU） elastomers were prepared based on different polyesters, polyethers and chain extenders. The structure, mechanical properties and cold resistant properties of PU were systematically inv...Six kinds of polyurethane （PU） elastomers were prepared based on different polyesters, polyethers and chain extenders. The structure, mechanical properties and cold resistant properties of PU were systematically investigated by FTIR, XRD, DMTA,universal testing machine and flex ductility machine. The results show that Tg of soft segment is the main factor of the cold resistant properties of polyurethane elastomer. Compared with the same relative molecular mass of the polyester and the polyether, the polyether flexibility is better, the glass transition temperature （Tg） is lower and the cold resistant properties is remarkable, for example the cold resistant properties of PU based on poly （tetramethylene glycol）, 1, 4-BG and MDI achieves the fifth level. The physics performances of polyurethane elastomers, such as breakdown strength, Young＇s modulus and the cold resistant properties, are all superior.展开更多
The therapeutic actions of Qing Luo Yin (QLY清络饮) with heat property and Wen Luo Yin (WLY温络饮) with cold property on pain, swelling of the ankle, arthritis index and ultrastructures of synoviocytes were compared i...The therapeutic actions of Qing Luo Yin (QLY清络饮) with heat property and Wen Luo Yin (WLY温络饮) with cold property on pain, swelling of the ankle, arthritis index and ultrastructures of synoviocytes were compared in rats of type II collagen-induced arthritis (CIA), with tripterygium glycosidorum (TG) used as control. The results indicated that both QLY and WLY could reduce pain, swelling of the ankle and the arthritis index of CIA, and QLY had better effects in reducing the swelling of the ankle and controlling the secondary pathological lesions as compared with WLY. Investigation on the ultrastructures of synoviocytes indicated that both QLY and WLY could reduce the number of Golgi apparatus, rough surface endoplasmic reticulum, dense bodies, matrix filaments and vacuoles so as to suppress the excessive secretion of synoviocytes in rats of CIA.展开更多
The Ti/Al/Ti clad plates exhibit a broad spectrum of potential applications.However,the conventional techniques of hot-pressing composite and explosive composite are intricate and environmentally hazardous.A novel met...The Ti/Al/Ti clad plates exhibit a broad spectrum of potential applications.However,the conventional techniques of hot-pressing composite and explosive composite are intricate and environmentally hazardous.A novel method was introduced for preparing clad plates,namely,the powder-in-tube method.This method involves a combination of cold rolling,annealing at a temperature of 550℃,and double rolling.The morphology of the intermetallic compound layer was analyzed through the utilization of interface stripping test,tensile test,and microscopic characterization.The interface morphology,interface bonding properties,tensile fracture structures,and properties of plates under the first and second rolling were compared,along with the effects of intermetallic compounds on the interface properties.The results indicate that the powder-in-tube method,when annealed at 550℃,can produce a composite plate featuring a complete and uniform Ti/Al interface.The obtained plate exhibits a peeling strength of 21.5 N/mm,tensile strength of 424 MPa,and elongation of 11.5%.Furthermore,a systematic analysis was conducted to determine the causes of performance degra-dation observed during annealing at temperatures of 600 and 650℃.展开更多
Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg)...Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg) were used in the experiment. Heart arrest was in-展开更多
To the Editor:Chinese herbal medicines(CHMs)are critical components of traditional Chinese medicine(TCM),[1]with their cold and hot properties being fundamental for guiding clinical applications and ensuring therapeut...To the Editor:Chinese herbal medicines(CHMs)are critical components of traditional Chinese medicine(TCM),[1]with their cold and hot properties being fundamental for guiding clinical applications and ensuring therapeutic efficacy.[2]However,the traditional method of identifying the cold and hot properties of CHMs relies heavily on the subjective experience of TCM practitioners and clinical practice,often leading to uncertainty and inconsistency.As such,there is a pressing need for more precise,rapid,and objective strategies to accurately identify the cold and hot properties of CHMs and their active ingredients.展开更多
A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points （PP） and the cold filter plugging points （CFPP） of biodiesel blends were evaluated on a low-temperatu...A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points （PP） and the cold filter plugging points （CFPP） of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals.展开更多
Palm fatty acid distillate(PFAD),a by-product of refining process of crude palm oil can be used as a potential feedstock for biodiesel production.However,the application of palm oil-based biodiesel is often hinder by ...Palm fatty acid distillate(PFAD),a by-product of refining process of crude palm oil can be used as a potential feedstock for biodiesel production.However,the application of palm oil-based biodiesel is often hinder by its poor cold flow properties(CFP).Biodiesel fuel with poor CFP may crystallize and result in clogging of fuel lines,filters and injectors that cause engine operability problems.For that,a vacuum distillation method was designed and its feasibility and efficiency in improving the CFP was examined.A total of 13.60wt%of total saturated fatty acid methyl esters were successfully removed from the PFAD biodiesel,resulting in the improvement of the cloud point(CP),cold filter plugging point(CFPP)and pour point(PP)of PFAD biodiesel from 20℃,19℃,and 15℃to 13℃,11℃,and 9℃,respectively.It is remarkable that the improved CFPP satisfied the requirements for grade C summer biodiesel for temperate climates in EN 14212 standard.Additionally,Sarin(U FAME)empirical correlation was evaluated and it was found to have a good prediction of CFP for PFAD biodiesel,with lower than 2℃deviation.展开更多
Maximum hardness test in weld heat-affected zone（HAZ）,oblique Y-groove cracking test and mechanical property test of welding joint of 1 000 MPa grade ultra-low carbon bainitic steel were carried out,so as to researc...Maximum hardness test in weld heat-affected zone（HAZ）,oblique Y-groove cracking test and mechanical property test of welding joint of 1 000 MPa grade ultra-low carbon bainitic steel were carried out,so as to research the weldability of the steel.The results show that the steel has lower cold cracking sensitivity,and preheating temperature of 100 ℃ can help completely eliminate cold cracks,generating good process weldability.The increase of preheating temperature can reduce the hardening degree of heat-affected zone.The strength of welding joint decreases and hardness reduces when heat inputs increase,and excellent mechanical properties can be obtained when low welding heat inputs are used.Fine lath bainites of different orientations combined with a few granular bainites that effectively split the original coarse austenite grains are the foundation of good properties.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
An experimental study was conducted to investigate the effects of four different additives on pour point and cloud point temperatures of a diesel fuel.Sample mixtures were prepared in different volumetric percentages ...An experimental study was conducted to investigate the effects of four different additives on pour point and cloud point temperatures of a diesel fuel.Sample mixtures were prepared in different volumetric percentages of four different additives(Ethanol,Toluene,n-Heptane and Xylene)and diesel fuel mixture.Pour point and cloud point temperatures of the blends were measured using standard ASTM D2500 and ASTM D97-96a methods,respectively.Introducing the additives to the diesel fuel did not lead to a significant reduction in cloud point temperature of the fuel.In fact,the greatest obtained reduction in cloud point temperature was achieved using 20 vol%or more of Toluene-diesel fuel mixtures.Although cloud points did not change significantly,even the slightest amounts of additives caused a high reduction in the pour point temperature of the fuel.Ethanol was the most effective additive in lowering the pour point temperature of the fuel.A 20%ethanol-fuel mixture caused nearly a 30reduction in the fuel pour point temperature.Therefore,knowing that none of the additives has a significant effect on cloud point temperature,while the greatest reduction in pour point temperature is achieved using ethanol even in low Vol%s,it can be concluded that the most efficient additive among these four additives to alter cold flow properties of a certain diesel fuel is Ethanol.展开更多
基金Hunan Provincial Natural Science Foundation(2022JJ30438)Natural Science Foundation of Changsha(kq2202260)Hunan Province Traditional Chinese Medicine Research Project(B2023039).
文摘Objective To develop a model based on a graph convolutional network(GCN)to achieve ef-ficient classification of the cold and hot medicinal properties of Chinese herbal medicines(CHMs).Methods After screening the dataset provided in the published literature,this study includ-ed 495 CHMs and their 8075 compounds.Three molecular descriptors were used to repre-sent the compounds:the molecular access system(MACCS),extended connectivity finger-print(ECFP),and two-dimensional(2D)molecular descriptors computed by the RDKit open-source toolkit(RDKit_2D).A homogeneous graph with CHMs as nodes was constructed and a classification model for the cold and hot medicinal properties of CHMs was developed based on a GCN using the molecular descriptor information of the compounds as node features.Fi-nally,using accuracy and F1 score to evaluate model performance,the GCN model was ex-perimentally compared with the traditional machine learning approaches,including decision tree(DT),random forest(RF),k-nearest neighbor(KNN),Naïve Bayes classifier(NBC),and support vector machine(SVM).MACCS,ECFP,and RDKit_2D molecular descriptors were al-so adopted as features for comparison.Results The experimental results show that the GCN achieved better performance than the traditional machine learning approach when using MACCS as features,with the accuracy and F1 score reaching 0.8364 and 0.8453,respectively.The accuracy and F1 score have increased by 0.8690 and 0.8120,respectively,compared with the lowest performing feature combina-tion OMER(only the combination of MACCS,ECFP,and RDKit_2D).The accuracy and F1 score of DT,RF,KNN,NBC,and SVM are 0.5051 and 0.5018,0.6162 and 0.6015,0.6768 and 0.6243,0.6162 and 0.6071,0.6364 and 0.6225,respectively.Conclusion In this study,by introducing molecular descriptors as features,it is verified that molecular descriptors and fingerprints play a key role in classifying the cold and hot medici-nal properties of CHMs.Meanwhile,excellent classification performance was achieved using the GCN model,providing an important algorithmic basis for the in-depth study of the“struc-ture-property”relationship of CHMs.
基金supported from the Natural Science Foundation Project of Shanghai(Nos.23ZR1425300 and 22ZR1426100)Experimental Technical Team Construction Project of Shanghai Education Commission(No.10110N230080)+1 种基金National Natural Science Foundation of China(No.22075183)Research and Innovation Project of Shanghai Municipal Education Commission(No.2023ZKZD54).
文摘The addition of cold flow improvers(CFIs)is considered as the optimum strategy to improve the cold flow properties(CFPs)of diesel fuels,but this strategy is always limited by the required large dosage.To obtain low-dosage and high-efficiency CFIs for diesel,1,2,3,6-tetrahydrophthalic anhydride(THPA)was introduced as a third and polar monomer to enhance the depressive effects of alkyl methacrylatetrans anethole copolymers(C_(14)MC-TA).The terpolymers of alkyl methacrylate-trans anethole-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-TA-THPA)were synthesized and compared with the binary copolymers of C_(14)MC-TA and alkyl methacrylate-1,2,3,6-tetrahydrophthalic anhydride(C_(14)MC-THPA).Results showed that C_(14)MC-THPA achieved the best depressive effects on the cold filter plugging point(CFPP)and solid point(SP)by 11℃and 16℃at a dosage of 1250 mg/L and monomer ratio of 6:1,while 1500mg/L C_(14)MC-TA(1:1)reached the optimal depressive effects on the CFPP and SP by 12℃and 18℃.THPA introduction significantly improved the depressive effects of C_(14)MC-TA.Lower dosages of C_(14)MCTA-THPA in diesel exerted better improvement effects on the CFPP and SP than that of C_(14)MC-TA and C_(14)MC-THPA.When the monomer ratio and dosage were 6:0.6:0.4 and 1000 mg/L,the improvement effect of C_(14)MC-TA-THPA on diesel reached the optimum level,and the CFPP and SP were reduced by 13℃and 19℃,respectively.A 3D nonlinear surface diagram fitted by a mathematical model was also used for the first time to better understand the relationships of monomer ratios,dosages,and depressive effects of CFIs in diesel.Surface analysis results showed that C_(14)MC-TA-THPA achieved the optimum depressive effects at a monomer ratio of 6:0.66:0.34 and dosage of 1000 mg/L,and the CFPP and SP decreased by 14℃ and 19℃,respectively.The predicted results were consistent with the actual ones.Additionally,the improvement mechanism of these copolymers in diesel was also explored.
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supported by the National Natural Science Foundation of China(Nos.22008155,22075183,21878188 and 21975161)Chenguang Program of Shanghai Education Devel-opment Foundation and Shanghai Municipal Education Commis-sion(No.19CG69).
文摘The high effective nano-hybrid pour point depressant(PPD)has attracted extensive attention for its po-tential application in improving the cold flow properties of diesel fuel.In this paper,the nano-hybrid PPD was prepared by melt-blending method using three different alkyl chain lengths(i.e.,tetradecyl,hexade-cyl,and octodecyl)of n-alkyl methacrylate-maleic anhydride copolymers(R 1 MC-MA,R 1=C_(14),C_(16),C_(18))and SiO_(2)nanoparticles.The effect of those nano-hybrid PPDs on the cold filter plugging point(CFPP)and solidifying point(SP)depressing of diesel fuel were studied.Results indicated that nano-hybrid PPD showed much better performance on diesel fuel.The diesel fuel treated with 0.2 wt%C_(14)MC-MA/SiO_(2)nano-hybrid PPD exhibited the best depression in CFPP and SP by 6℃ and 18℃,respectively,which higher than that of single C 14 MC-MA.Viscosity-temperature curves and polarized optical microscopy were conducted to explore the performance mechanism;and results presented that nano-hybrid PPD of C_(14)MC-MA/SiO_(2)could effectively lower the low-temperature viscosity,and modify the crystallization behavior and crystal morphology of diesel.Therefore,the cold flow properties of diesel were significantly improved.
基金Funded by the Key Laboratory of Enviroment-friendly Polymer Materials of Anhui ProvinceNational Laboratory for Physical Sciences at the Microscale and Anli Artificial Leather co. ltd, China
文摘Six kinds of polyurethane （PU） elastomers were prepared based on different polyesters, polyethers and chain extenders. The structure, mechanical properties and cold resistant properties of PU were systematically investigated by FTIR, XRD, DMTA,universal testing machine and flex ductility machine. The results show that Tg of soft segment is the main factor of the cold resistant properties of polyurethane elastomer. Compared with the same relative molecular mass of the polyester and the polyether, the polyether flexibility is better, the glass transition temperature （Tg） is lower and the cold resistant properties is remarkable, for example the cold resistant properties of PU based on poly （tetramethylene glycol）, 1, 4-BG and MDI achieves the fifth level. The physics performances of polyurethane elastomers, such as breakdown strength, Young＇s modulus and the cold resistant properties, are all superior.
文摘The therapeutic actions of Qing Luo Yin (QLY清络饮) with heat property and Wen Luo Yin (WLY温络饮) with cold property on pain, swelling of the ankle, arthritis index and ultrastructures of synoviocytes were compared in rats of type II collagen-induced arthritis (CIA), with tripterygium glycosidorum (TG) used as control. The results indicated that both QLY and WLY could reduce pain, swelling of the ankle and the arthritis index of CIA, and QLY had better effects in reducing the swelling of the ankle and controlling the secondary pathological lesions as compared with WLY. Investigation on the ultrastructures of synoviocytes indicated that both QLY and WLY could reduce the number of Golgi apparatus, rough surface endoplasmic reticulum, dense bodies, matrix filaments and vacuoles so as to suppress the excessive secretion of synoviocytes in rats of CIA.
基金supported by the 1ll Project(B16009)the National Key Research and Development Program of China(2017YFB0304105).
文摘The Ti/Al/Ti clad plates exhibit a broad spectrum of potential applications.However,the conventional techniques of hot-pressing composite and explosive composite are intricate and environmentally hazardous.A novel method was introduced for preparing clad plates,namely,the powder-in-tube method.This method involves a combination of cold rolling,annealing at a temperature of 550℃,and double rolling.The morphology of the intermetallic compound layer was analyzed through the utilization of interface stripping test,tensile test,and microscopic characterization.The interface morphology,interface bonding properties,tensile fracture structures,and properties of plates under the first and second rolling were compared,along with the effects of intermetallic compounds on the interface properties.The results indicate that the powder-in-tube method,when annealed at 550℃,can produce a composite plate featuring a complete and uniform Ti/Al interface.The obtained plate exhibits a peeling strength of 21.5 N/mm,tensile strength of 424 MPa,and elongation of 11.5%.Furthermore,a systematic analysis was conducted to determine the causes of performance degra-dation observed during annealing at temperatures of 600 and 650℃.
文摘Objective To study the mechanism of myocardial dielectric property changes in radio frequency during hypothermic preservation and explore myocardial viability evaluative method. Methods Hybrid young pigs ( 20 - 30 kg) were used in the experiment. Heart arrest was in-
基金supported by the Scientific and Technological Innovation Project of China Academy of Chinese Medical Sciences(CACMS)(No.CI2023C065YLL)Scientific and technological innovation project of CACMS(No.CI2021B003)+1 种基金CACMS Innovation Fund(No.CI2021A01509)National Natural Science Foundation of China(No.61872297).
文摘To the Editor:Chinese herbal medicines(CHMs)are critical components of traditional Chinese medicine(TCM),[1]with their cold and hot properties being fundamental for guiding clinical applications and ensuring therapeutic efficacy.[2]However,the traditional method of identifying the cold and hot properties of CHMs relies heavily on the subjective experience of TCM practitioners and clinical practice,often leading to uncertainty and inconsistency.As such,there is a pressing need for more precise,rapid,and objective strategies to accurately identify the cold and hot properties of CHMs and their active ingredients.
基金the financial support of the Natural Science Foundation of Chongqing(project No.CSTC2006BA6031)the Program for New Century Excellent Talents in Chinese Universities(project No.NCET-04-1002)
文摘A soybean oil derived biodiesel was prepared and blended with a conventional No. 0 petrodiesel. The pour points （PP） and the cold filter plugging points （CFPP） of biodiesel blends were evaluated on a low-temperature flow tester. Dynamic viscosities of the blends at different temperatures and different shear rates were measured on a rotary rheometer. The crystal morphologies of biodiesel blends at low temperatures were analyzed using a polarizing microscope. The results indicated that blended fuels demonstrated slight decrease in PPs and CFPPs as compared with those of neat soybean oil derived biodiesel and pure petrodiesel. Below the temperatures of PPs or CFPPs, the dynamic viscosity of biodiesel blends dramatically increased with a decreasing temperature, but decreased with an increasing shear rate, so that biodiesel blends exhibited non-Newtonian behavior. At temperatures higher than PPs or CFPPs, a linear relationship appeared between the dynamic viscosity and shear rate and biodiesel blends became Newtonian fluids. At low temperatures, wax crystals of biodiesel blends grew and agglomerated rapidly. Loss of fluidity for biodiesel blends at low temperatures could therefore be attributed on one hand to the sharp increase of viscosity and on the other hand to the rapid growth and agglomeration of wax crystals.
基金supported by the Malaysian Ministry of Higher Education(No.FRGS/2/2014/TK06/CURTIN/02/1).
文摘Palm fatty acid distillate(PFAD),a by-product of refining process of crude palm oil can be used as a potential feedstock for biodiesel production.However,the application of palm oil-based biodiesel is often hinder by its poor cold flow properties(CFP).Biodiesel fuel with poor CFP may crystallize and result in clogging of fuel lines,filters and injectors that cause engine operability problems.For that,a vacuum distillation method was designed and its feasibility and efficiency in improving the CFP was examined.A total of 13.60wt%of total saturated fatty acid methyl esters were successfully removed from the PFAD biodiesel,resulting in the improvement of the cloud point(CP),cold filter plugging point(CFPP)and pour point(PP)of PFAD biodiesel from 20℃,19℃,and 15℃to 13℃,11℃,and 9℃,respectively.It is remarkable that the improved CFPP satisfied the requirements for grade C summer biodiesel for temperate climates in EN 14212 standard.Additionally,Sarin(U FAME)empirical correlation was evaluated and it was found to have a good prediction of CFP for PFAD biodiesel,with lower than 2℃deviation.
基金Item Sponsored by National Science and Technology Support Plan Project of China(2007BAE51B07)
文摘Maximum hardness test in weld heat-affected zone（HAZ）,oblique Y-groove cracking test and mechanical property test of welding joint of 1 000 MPa grade ultra-low carbon bainitic steel were carried out,so as to research the weldability of the steel.The results show that the steel has lower cold cracking sensitivity,and preheating temperature of 100 ℃ can help completely eliminate cold cracks,generating good process weldability.The increase of preheating temperature can reduce the hardening degree of heat-affected zone.The strength of welding joint decreases and hardness reduces when heat inputs increase,and excellent mechanical properties can be obtained when low welding heat inputs are used.Fine lath bainites of different orientations combined with a few granular bainites that effectively split the original coarse austenite grains are the foundation of good properties.
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.
文摘An experimental study was conducted to investigate the effects of four different additives on pour point and cloud point temperatures of a diesel fuel.Sample mixtures were prepared in different volumetric percentages of four different additives(Ethanol,Toluene,n-Heptane and Xylene)and diesel fuel mixture.Pour point and cloud point temperatures of the blends were measured using standard ASTM D2500 and ASTM D97-96a methods,respectively.Introducing the additives to the diesel fuel did not lead to a significant reduction in cloud point temperature of the fuel.In fact,the greatest obtained reduction in cloud point temperature was achieved using 20 vol%or more of Toluene-diesel fuel mixtures.Although cloud points did not change significantly,even the slightest amounts of additives caused a high reduction in the pour point temperature of the fuel.Ethanol was the most effective additive in lowering the pour point temperature of the fuel.A 20%ethanol-fuel mixture caused nearly a 30reduction in the fuel pour point temperature.Therefore,knowing that none of the additives has a significant effect on cloud point temperature,while the greatest reduction in pour point temperature is achieved using ethanol even in low Vol%s,it can be concluded that the most efficient additive among these four additives to alter cold flow properties of a certain diesel fuel is Ethanol.
