Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and...Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.展开更多
The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction elect...The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10–15 s,with minimal sample(<0.5 mg)and solvent consumption(<20μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R^(2)X>0.87,R^(2)Y>0.91,and Q^(2)>0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.展开更多
Fracture networks within hot dry rock(HDR)geothermal reservoirs are complex,and heat extraction via water injection is thus a coupled process of heat-fluid-solid multifield.In this paper,utilizing the theory of normal...Fracture networks within hot dry rock(HDR)geothermal reservoirs are complex,and heat extraction via water injection is thus a coupled process of heat-fluid-solid multifield.In this paper,utilizing the theory of normally distributed random functions,we develop a corresponding pre-processing subprogram to establish a discrete network model of complex fracture distribution in HDR reservoirs;then construct a heat-fluid-solid finite element model for heat extraction via water injection and compare the numerical solution with the analytical solution of the one-dimensional non-isothermal consolidation problem for verification.The numerical simulation results show that the main factors affecting the heat extraction efficiency of HDR reservoirs include fracture width,fracture density,fracture permeability,and matrix permeability.When a HDR reservoir is injected with water for heat extraction,there is a certain threshold value of these influential parameters,beyond which the outlet temperature drops significantly,resulting in an obvious thermal breakthrough.When injecting water for heat extraction,the values of these parameters should be controlled and kept at a reasonable level,otherwise,the HDR reservoir may enter a thermal breakthrough stage in advance,which is not conducive for long-period heat extraction.Influenced by the random distribution of complex fractures,the leading edge of the cold front may present an irregular distribution.During the process of heat extraction,the stress gradually changes from a compressional state to a tensile state,which induces further damage to the HDR reservoir.展开更多
Numerous intersected rock fractures constitute the fracture network in enhanced geothermal systems.The complicated convective heat transfer behavior in intersected fractures is critical to the heat recovery in fractur...Numerous intersected rock fractures constitute the fracture network in enhanced geothermal systems.The complicated convective heat transfer behavior in intersected fractures is critical to the heat recovery in fractured geothermal reservoirs.A series of three-dimensional intersected fracture models is constructed to perform the flow-through heat transfer simulations.The geometry effects of dead-end fractures(DEFs)on the heat transfer are evaluated in terms of intersected angles,apertures,lengths,and the connectivity.The results indicate that annular streamlines appear in the rough DEF and cause an ellipse distribution of the cold front.Compared to plate DEFs,the fluid flow in the rough DEF enhances the heat transfer.Both the increment of outlet water temperatureΔToutand the ratio of heat production Qrpresent the largest at the intersected angle of 90°while decline with the decrease of the intersected angle between the main flow fracture(MFF)and the DEFs.The extension of the length of intersected DEFs is beneficial to heat production while enhancing its aperture is not needed.Solely increasing the number of intersected DEFs induces a little increase of heat extraction,and more significant heat production can be obtained through connecting these DEFs with the MFF forming the flow network.展开更多
Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(...Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.展开更多
A novel experimental setup was developed to study the heat extraction of geothermal heat exchanger(GHE)in different operational modes under adiabatic and isothermal boundaries.The experimental setup consists of a sand...A novel experimental setup was developed to study the heat extraction of geothermal heat exchanger(GHE)in different operational modes under adiabatic and isothermal boundaries.The experimental setup consists of a sand trunk,a tailored water chiller,a natural cold source unit,two water boxes containing hot water and cool water,and a data acquisition system.The experimental results indicate that the volume flow rate of the entering water is a main factor affecting the heat extraction;furthermore,the heat extraction value per meter pipe decreases gradually along the heat extraction pipe and increases with the increase of the incoming water volume flow rate.Therefore,this novel experimental setup may be helpful to further study the operation performance of GHE in different types of soil.展开更多
This experiment was conducted to evaluate the effects of Bupleurum extract (BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were rando...This experiment was conducted to evaluate the effects of Bupleurum extract (BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg-1 dry matter. Supplementation with BE decreased (P〈0.05) blood urea nitrogen (BUN) contents and increased blood total protein (TP) and albumin (ALB) levels compared with control cows, but it had no effects (P〉0.05) on blood glucose (GLU), nonesterified fatty acid (NEFA), total triglycedde (TG), low-density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C). Compared with control cows, cows fed BE had higher (P〈0.05) superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. However, supplementation with BE had no effect (P〉0.05) on total antioxidant capacity (T-AOC) or malondialdehyde (MDA) levels. The immunoglobulin (Ig) A and G contents increased (P〈0.05) in cows fed 0.25 or 0.5 g of BE kg-1. Interleukin (IL)-2 and IL-4 levels were higher (P〈0.05) in cows fed 0.5 and 1.0 g of BE kg-1, and IL-6 was significantly elevated (P〈0.05) in cows fed 0.5 g of BE kg-1. There were no treatment effects (P〉0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ratio, or tumor necrosis factor-α (TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.展开更多
We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventi...We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventional methods, a very high extraction yield of good quality agarose (as high as 39 wt%) could be achieved depending upon the nature of used IL and applied experimental conditions. Purity of extracted agarose was confirmed from various spectral and analytical techniques, such as 1H and 13C NMR, FTIR, circular dichroism (CD), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The physicochemical properties, such as gelling or melting temperature, viscosity and gel strength of extracted agarose hydrogels have been measured and compared with the agarose obtained from similar source reported in the literature. ILs were recovered after the extraction of agarose and were reused for further extraction experiments. % Recycling and extraction ability of recycled ILs in different cycles have been measured. The developed extraction process of utilizing ILs as medium is easy, simple and highly efficient as compared to the conventional methods of agarose extraction from algae.展开更多
The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on i...The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology (RSM) technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.展开更多
Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease (COPD). The purpose of this study was to investigate genotoxicity and heat shock protein 70 (H...Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease (COPD). The purpose of this study was to investigate genotoxicity and heat shock protein 70 (Hsp70) in human airway smooth muscle cells (HASMCs) exposed to cigarette smoke extract (CSE). HASMCs was exposed to CSE with different doses for 24 h. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined by using HPLC-ECD, the DNA damage was ana- lyzed by using comet assay, and apoptosis was examined by using Annexin-FITC/PI staining. The pro- duction of Hsp70 after CSE stimulation was tested. Results indicated that CSE significantly increased the level of 8-OHdG, DNA damage and cell apoptosis, and reduced the production of Hsp70. In par- ticular, levels of Hsp70 were inversely correlated with 8-OHdG, DNA damage and cell apoptosis. It was concluded that cigarette smoke induced genotoxicity and decreased the production of cell protective protein Hsp70, which may contribute to the development of some airway diseases.展开更多
In this work, the extractive distillation with heat integration process is extended to separate the pressure-insensitive benzene-cyclohexane azeotrope by using furfural as the entrainer. The optimal design of extracti...In this work, the extractive distillation with heat integration process is extended to separate the pressure-insensitive benzene-cyclohexane azeotrope by using furfural as the entrainer. The optimal design of extractive distillation process is established to achieve minimum energy requirement using the multi-objective genetic algorithm, and the results show that energy saving for this heat integration process is 15.7%. Finally, the control design is performed to investigate the system's dynamic performance, and three control structures are studied. The pressure-compensated temperature control scheme is proposed based on the first two control structures, and the dynamic responses reveal that the feed disturbances in both flow rate and benzene composition can be mitigated well.展开更多
Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces ...Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces microflavus (TSS) on turf performance and physiological activities of tall fescue (Festuca arundinacea) in response to heat stress. Plants of tall fescue cultivar ‘Barlexus’ were exposed to 38/33 (°C) (day/night) high temperature in growth chamber after TSS applications. High temperature induced about 3.5 fold increases of initial shoot extension rate and clipping yield (6 d) and led to quick decline of plant growth after 18 d. TSS inhibited the extent of initial increases of shoot extension rate and clipping yield and maintained a longer period of steady growth under the heat stress. TSS also decreased the decline of leaf chlorophyll content, TNC, shoot density, and turf quality induced by heat stress. The results suggested that TSS application improved turf performance under heat stress, and the greater improvement of heat tolerance was associated with higher dose of application. This positive effect on heat tolerance could be related to the decreased carbohydrate consumption and loss, and reduced decomposition of leaf chlorophyll.展开更多
[Objectives]This study was conducted to investigate the extraction method of Impatiens balsamina L.(Tougucao),and to optimize the extraction process conditions and parameters.[Methods]Different ethanol concentrations,...[Objectives]This study was conducted to investigate the extraction method of Impatiens balsamina L.(Tougucao),and to optimize the extraction process conditions and parameters.[Methods]Different ethanol concentrations,ethanol amounts and extraction time were investigated by an orthogonal test L_(9)(3^(4))and high performance liquid chromatography(HPLC),and the extraction process parameters were evaluated by the yield of extract and the content of quercetin.[Results]Under the three optimal extraction conditions of impregnation,heating reflux and ultrasound,the extract yield and quercetin contents of I.balsamina were 8.27%,9.50%,7.09%and 1.60,3.05,3.03μg/g,respectively.Heating reflux extraction and ultrasonic extraction showed higher extract yields and quercetin contents of I.balsamina,while the values were lower under the impregnation extraction conditions.The primary and secondary factors were:ethanol amount(C)>ethanol concentration(A)>extraction time(B).The optimal extraction process of I.balsamina was as follows:adding 10 times of 60%ethanol and ultrasonically extracting for 30 min.[Conclusions]The method is simple,convenient,accurate and reliable,and provides a scientific basis for the research on the extraction process of I.balsamina and its preparations.展开更多
基金YVSG was funded by a doctoral scholarship provided by the Peruvian National Fund,for Scientific,Technological,and Technological Innovation Development(FONDECYT)the funding branch of the National Council for Science,Technological,and Technological Innovation Development(CONCYTEC),Peru(grant contract No 233-2015-FONDECYT).
文摘Background Heat stress has severe negative consequences on performance and health of pigs,leading to significant economic losses.The objective of this study was to investigate the effects of supplemental vitamin E and a botanical extract in feed or drinking water on growth performance,intestinal health,and oxidative and immune status in grow-ing pigs housed under heat stress conditions.Methods Duplicate experiments were conducted,each using 64 crossbred pigs with an initial body weight of 50.7±3.8 and 43.9±3.6 kg and age of 13-week and 12-week,respectively.Pigs(n=128)were housed individually and assigned within weight blocks and sex to a 2×4 factorial arrangement consisting of 2 environments(thermo-neutral(21.2℃)or heat-stressed(30.9℃))and 4 supplementation treatments(control diet;control+100 IU/L of D-α-tocopherol in water;control+200 IU/kg of DL-α-tocopheryl-acetate in feed;or control+400 mg/kg of a botanical extract in feed).Results Heat stress for 28 d reduced(P≤0.001)final body weight,average daily gain,and average daily feed intake(-7.4 kg,-26.7%,and-25.4%,respectively)but no effects of supplementation were detected(P>0.05).Serum vitamin E increased(P<0.001)with vitamin E supplementation in water and in feed(1.64 vs.3.59 and 1.64 vs.3.24),but not for the botanical extract(1.64 vs.1.67 mg/kg)and was greater when supplemented in water vs.feed(P=0.002).Liver vitamin E increased(P<0.001)with vitamin E supplementations in water(3.9 vs.31.8)and feed(3.9 vs.18.0),but not with the botanical extract(3.9 vs.4.9 mg/kg).Serum malondialdehyde was reduced with heat stress on d 2,but increased on d 28(interaction,P<0.001),and was greater(P<0.05)for antioxidant supplementation compared to control.Cellular proliferation was reduced(P=0.037)in the jejunum under heat stress,but increased in the ileum when vitamin E was supplemented in feed and water under heat stress(interaction,P=0.04).Tumor necrosis factor-αin jejunum and ileum mucosa decreased by heat stress(P<0.05)and was reduced by vitamin E sup-plementations under heat stress(interaction,P<0.001).Conclusions The addition of the antioxidants in feed or in drinking water did not alleviate the negative impact of heat stress on feed intake and growth rate of growing pigs.
基金supported by the CACMS Innovation Fund,China(Grant Nos.:CI2021A04504 and CI2021A05206)the National Natural Science Foundation of China(Grant Nos.:82104380,81891010,81891013,and 82074012)+2 种基金the Fundamental Research Funds for the Central Public Welfare Research Institutes,China(Grant Nos.:ZZ14-YQ-047 and ZZXT202105)the Key Project at Central Government Level(Grant No.:2060302-2201-26)the Beijing Nova Program.
文摘The rapid and accurate authentication of traditional Chinese medicines(TCMs)has always been a key scientific and technical problem in the field of pharmaceutical analysis.Herein,a novel heating online extraction electrospray ionization mass spectrometry(H-oEESI-MS)was developed for the rapid and direct analysis of extremely complex substances without the requirement for any sample pretreatment or pre-separation steps.The overall molecular profile and fragment structure features of various herbal medicines could be completely captured within 10–15 s,with minimal sample(<0.5 mg)and solvent consumption(<20μL for one sample).Furthermore,a rapid differentiation and authentication strategy for TCMs based on H-oEESI-MS was proposed,including metabolic profile characterization,characteristic marker screening and identification,and multivariate statistical analysis model validation.In an analysis of 52 batches of seven types of Aconitum medicinal materials,20 and 21 key compounds were screened out as the characteristic markers of raw and processed Aconitum herbal medicines,respectively,and the possible structures of all the characteristic markers were comprehensively identified based on Compound Discoverer databases.Finally,multivariate statistical analysis showed that all the different types of herbal medicines were well differentiated and identified(R^(2)X>0.87,R^(2)Y>0.91,and Q^(2)>0.72),which further verified the feasibility and reliability of this comprehensive strategy for the rapid authentication of different TCMs based on H-oEESI-MS.In summary,this rapid authentication strategy realized the ultra-high-throughput,low-cost,and standardized detection of various complex TCMs for the first time,thereby demonstrating wide applicability and value for the development of quality standards for TCMs.
基金This work is financially supported by the National Science Foundation of China(Grant No.52192622,No.51936001,No.52274002,No.51804033 and No.U20A20265)Beijing Natural Science Foundation(Grant No.3222030)+2 种基金the PetroChina Science and Technology Innovation Foundation Project(2021DQ02e0201)the Award Cultivation Foundation from Beijing Institute of Petrochemical Technology(Grant No.BIPTACF-002)the Fund of the Beijing Municipal Education Commission(Grant No.22019821001).
文摘Fracture networks within hot dry rock(HDR)geothermal reservoirs are complex,and heat extraction via water injection is thus a coupled process of heat-fluid-solid multifield.In this paper,utilizing the theory of normally distributed random functions,we develop a corresponding pre-processing subprogram to establish a discrete network model of complex fracture distribution in HDR reservoirs;then construct a heat-fluid-solid finite element model for heat extraction via water injection and compare the numerical solution with the analytical solution of the one-dimensional non-isothermal consolidation problem for verification.The numerical simulation results show that the main factors affecting the heat extraction efficiency of HDR reservoirs include fracture width,fracture density,fracture permeability,and matrix permeability.When a HDR reservoir is injected with water for heat extraction,there is a certain threshold value of these influential parameters,beyond which the outlet temperature drops significantly,resulting in an obvious thermal breakthrough.When injecting water for heat extraction,the values of these parameters should be controlled and kept at a reasonable level,otherwise,the HDR reservoir may enter a thermal breakthrough stage in advance,which is not conducive for long-period heat extraction.Influenced by the random distribution of complex fractures,the leading edge of the cold front may present an irregular distribution.During the process of heat extraction,the stress gradually changes from a compressional state to a tensile state,which induces further damage to the HDR reservoir.
基金financially supported by the National Key R&D Program of China(Grant No.2019YFB1504103)the China Postdoctoral Science Foundation(Grant Nos.2019TQ0174)。
文摘Numerous intersected rock fractures constitute the fracture network in enhanced geothermal systems.The complicated convective heat transfer behavior in intersected fractures is critical to the heat recovery in fractured geothermal reservoirs.A series of three-dimensional intersected fracture models is constructed to perform the flow-through heat transfer simulations.The geometry effects of dead-end fractures(DEFs)on the heat transfer are evaluated in terms of intersected angles,apertures,lengths,and the connectivity.The results indicate that annular streamlines appear in the rough DEF and cause an ellipse distribution of the cold front.Compared to plate DEFs,the fluid flow in the rough DEF enhances the heat transfer.Both the increment of outlet water temperatureΔToutand the ratio of heat production Qrpresent the largest at the intersected angle of 90°while decline with the decrease of the intersected angle between the main flow fracture(MFF)and the DEFs.The extension of the length of intersected DEFs is beneficial to heat production while enhancing its aperture is not needed.Solely increasing the number of intersected DEFs induces a little increase of heat extraction,and more significant heat production can be obtained through connecting these DEFs with the MFF forming the flow network.
基金The financial support from the National Natural Science Foundation of China(Nos.41772154 and 42102338)Natural Science Foundation of Shandong Province(Nos.ZR2019MA009 and ZR2020QE115)SDUST Research Fund of China(No.2018TDJH102)。
文摘Heat production from geothermal reservoirs is a typical heat transfer process involving a cold working fluid contacting a hot rock formation.Compared to the thermal-physical characteristics of water,supercritical CO_(2)(scCO_(2))has a higher heat storage capacity over a wide temperature-pressure range and may be favored as a heat transfer fluid.Singularly characteristic of scCO_(2)-based heat extraction is that the hydraulic-thermal properties of the scCO_(2) vary dramatically and dynamically with the spatial pressure gradient during unsteady-state flow along fracture.This highly nonlinear behavior presents a challenge in the accurate estimation of heat extraction efficiency in scCO_(2)-based EGS.In this paper,a thermal-h ydraulic-mechanical(THM)coupled model is developed by considering deformation of the fractured reservoir,non-Darcy flow and the varying thermal-physical properties of scCO_(2).The proposed model is validated by matching the modeling temperature distribution with published data.The results show that during continuous injection of scCO_(2),the fracture first widens and then narrows,ultimately reopening over the long term.The sequential fracture deformation behaviors are in response to the combined impacts of mechanical compression and thermally-induced deformation.By controlling the injection parameters of the scCO_(2),it is found that the heat extraction rate is positively correlated to its pore pressure or mass flow rate.The heat extraction rate can be significantly enhanced,when the inlet temperature of scCO_(2) is below its critical temperature.As a result,the heat increment recovered per unit mass of scCO_(2) decreases as the hot rock is gradually cooled.Meanwhile,the heat increment recovered per unit mass of scCO_(2) decreases by increasing the inlet temperature of scCO_(2) or its mass flow rate,but increases as the outlet pressure rises.Furthermore,multi-linear regression indicates that controlling the inlet temperature of the scCO_(2) can significantly improve the thermodynamic efficiency of heat extraction.
基金Sponsored by the National Natural Science Foundation of China (Grant No. 50378024)
文摘A novel experimental setup was developed to study the heat extraction of geothermal heat exchanger(GHE)in different operational modes under adiabatic and isothermal boundaries.The experimental setup consists of a sand trunk,a tailored water chiller,a natural cold source unit,two water boxes containing hot water and cool water,and a data acquisition system.The experimental results indicate that the volume flow rate of the entering water is a main factor affecting the heat extraction;furthermore,the heat extraction value per meter pipe decreases gradually along the heat extraction pipe and increases with the increase of the incoming water volume flow rate.Therefore,this novel experimental setup may be helpful to further study the operation performance of GHE in different types of soil.
基金supported financially by the National Key Research and Development Program of China (2016YFD0500503)the Agricultural Science and Technology Innovation Program, China (ASTIP-IAS12)the Anhui International Science and Technology Cooperation Plan Program, China (1503062019)
文摘This experiment was conducted to evaluate the effects of Bupleurum extract (BE) on blood metabolites, antioxidant status, and immune function in dairy cows under heat stress. Forty lactating Holstein cows were randomly assigned to 1 of 4 treatments. The treatments consisted of 0, 0.25, 0.5, and 1.0 g of BE kg-1 dry matter. Supplementation with BE decreased (P〈0.05) blood urea nitrogen (BUN) contents and increased blood total protein (TP) and albumin (ALB) levels compared with control cows, but it had no effects (P〉0.05) on blood glucose (GLU), nonesterified fatty acid (NEFA), total triglycedde (TG), low-density lipoprotein cholesterol (LDL-C), and high density lipoprotein cholesterol (HDL-C). Compared with control cows, cows fed BE had higher (P〈0.05) superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activity. However, supplementation with BE had no effect (P〉0.05) on total antioxidant capacity (T-AOC) or malondialdehyde (MDA) levels. The immunoglobulin (Ig) A and G contents increased (P〈0.05) in cows fed 0.25 or 0.5 g of BE kg-1. Interleukin (IL)-2 and IL-4 levels were higher (P〈0.05) in cows fed 0.5 and 1.0 g of BE kg-1, and IL-6 was significantly elevated (P〈0.05) in cows fed 0.5 g of BE kg-1. There were no treatment effects (P〉0.05) on the CD4+ and CD8+ T lymphocyte ratios, CD4+/CD8+ratio, or tumor necrosis factor-α (TNF-α) level among the groups. These findings suggest that BE supplementation may improve protein metabolism, in addition to enhancing antioxidant activity and immune function in heat-stressed dairy cows.
文摘We explored the possibility of using ionic liquids (ILs) as medium for efficient extraction of agarose via dissolution of red algae under varying conditions of heating or microwave irradiation. As compared to conventional methods, a very high extraction yield of good quality agarose (as high as 39 wt%) could be achieved depending upon the nature of used IL and applied experimental conditions. Purity of extracted agarose was confirmed from various spectral and analytical techniques, such as 1H and 13C NMR, FTIR, circular dichroism (CD), gel permeation chromatography (GPC) and thermogravimetric analysis (TGA). The physicochemical properties, such as gelling or melting temperature, viscosity and gel strength of extracted agarose hydrogels have been measured and compared with the agarose obtained from similar source reported in the literature. ILs were recovered after the extraction of agarose and were reused for further extraction experiments. % Recycling and extraction ability of recycled ILs in different cycles have been measured. The developed extraction process of utilizing ILs as medium is easy, simple and highly efficient as compared to the conventional methods of agarose extraction from algae.
基金Project(2013AA064003)supported by the National High Technology Research and Development Program of ChinaProject(2012HB008)supported by Young and Middle-aged Academic Technology Leader Backup Talent Cultivation Program in Yunnan Province,China
文摘The technology that waste activated carbon after extracting gold is regenerated with steam under microwave heating was studied. The influence of the activation temperature, activation duration and steam flow rate on iodine adsorption value and regeneration yield of activated carbon was investigated. The response surface methodology (RSM) technique was utilized to optimize the process conditions. The optimum conditions for the preparation of activated carbon are identified to be activation temperature of 831 ℃, activation duration of 40 min and steam flow rate of 2.67 mL/min. The optimum conditions result in an activated carbon with an iodine number of 1048 mg/g and a yield of 40%, and the BET surface area evaluated using nitrogen adsorption isotherm is 1493 m2/g, with total pore volume of 1.242 cm3/g. And the pore structure of activated carbon regenerated is mainly composed of micropores and a small amount of mesopores.
基金supported by grants from the National Natural Science Foundation of China(No.8107003681370145+3 种基金81370156 and 81070021)The National Key Technology R&D Program of the 12th National Five-year Development Plan:Clinical Study on Translational Medicine of Respiratory Disease(No.212BA105B01)The Specific Project of National Health Research Project of Ministry of Health of China(No.201002008)Program for Changjiang Scholars and Innovative Research Team in University(No.PCSIRT1131)
文摘Cigarette smoke is associated with the development of several diseases, such as chronic ob- structive pulmonary disease (COPD). The purpose of this study was to investigate genotoxicity and heat shock protein 70 (Hsp70) in human airway smooth muscle cells (HASMCs) exposed to cigarette smoke extract (CSE). HASMCs was exposed to CSE with different doses for 24 h. The level of 8-hydroxydeoxyguanosine (8-OHdG) was determined by using HPLC-ECD, the DNA damage was ana- lyzed by using comet assay, and apoptosis was examined by using Annexin-FITC/PI staining. The pro- duction of Hsp70 after CSE stimulation was tested. Results indicated that CSE significantly increased the level of 8-OHdG, DNA damage and cell apoptosis, and reduced the production of Hsp70. In par- ticular, levels of Hsp70 were inversely correlated with 8-OHdG, DNA damage and cell apoptosis. It was concluded that cigarette smoke induced genotoxicity and decreased the production of cell protective protein Hsp70, which may contribute to the development of some airway diseases.
基金supported by the National Natural Science Foundation of China(grant number 21476261)the Key Research and Development Plan Project of Shandong Province(grant number 2015GGX107004)
文摘In this work, the extractive distillation with heat integration process is extended to separate the pressure-insensitive benzene-cyclohexane azeotrope by using furfural as the entrainer. The optimal design of extractive distillation process is established to achieve minimum energy requirement using the multi-objective genetic algorithm, and the results show that energy saving for this heat integration process is 15.7%. Finally, the control design is performed to investigate the system's dynamic performance, and three control structures are studied. The pressure-compensated temperature control scheme is proposed based on the first two control structures, and the dynamic responses reveal that the feed disturbances in both flow rate and benzene composition can be mitigated well.
基金Item supported by national natural sciencefoundation of China(No.30270089)science and technologycommission of Shanghai(No.03JC14047)
文摘Heat stress in summer is a major factor limiting use of cool-season grasses in Shanghai area, China. The objectives of this study were to investigate effects of a crude extract product of a new strain of Streptomyces microflavus (TSS) on turf performance and physiological activities of tall fescue (Festuca arundinacea) in response to heat stress. Plants of tall fescue cultivar ‘Barlexus’ were exposed to 38/33 (°C) (day/night) high temperature in growth chamber after TSS applications. High temperature induced about 3.5 fold increases of initial shoot extension rate and clipping yield (6 d) and led to quick decline of plant growth after 18 d. TSS inhibited the extent of initial increases of shoot extension rate and clipping yield and maintained a longer period of steady growth under the heat stress. TSS also decreased the decline of leaf chlorophyll content, TNC, shoot density, and turf quality induced by heat stress. The results suggested that TSS application improved turf performance under heat stress, and the greater improvement of heat tolerance was associated with higher dose of application. This positive effect on heat tolerance could be related to the decreased carbohydrate consumption and loss, and reduced decomposition of leaf chlorophyll.
基金Supported by Scientific Research Project of Guizhou University of Traditional Chinese Medicine([2019]64)。
文摘[Objectives]This study was conducted to investigate the extraction method of Impatiens balsamina L.(Tougucao),and to optimize the extraction process conditions and parameters.[Methods]Different ethanol concentrations,ethanol amounts and extraction time were investigated by an orthogonal test L_(9)(3^(4))and high performance liquid chromatography(HPLC),and the extraction process parameters were evaluated by the yield of extract and the content of quercetin.[Results]Under the three optimal extraction conditions of impregnation,heating reflux and ultrasound,the extract yield and quercetin contents of I.balsamina were 8.27%,9.50%,7.09%and 1.60,3.05,3.03μg/g,respectively.Heating reflux extraction and ultrasonic extraction showed higher extract yields and quercetin contents of I.balsamina,while the values were lower under the impregnation extraction conditions.The primary and secondary factors were:ethanol amount(C)>ethanol concentration(A)>extraction time(B).The optimal extraction process of I.balsamina was as follows:adding 10 times of 60%ethanol and ultrasonically extracting for 30 min.[Conclusions]The method is simple,convenient,accurate and reliable,and provides a scientific basis for the research on the extraction process of I.balsamina and its preparations.