The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from ...The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from Russia. The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%. When the concentration of carbon dioxide was higher than 26%, the volume of the heavy phase decreased, and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil. When the concentration of carbon dioxide in the mixture was 26%, the effect of viscosity reducing to the heavy phase was the strongest. The density of the light and heavy phases, volume factor, and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture. The best concentration of carbon dioxide in the mixture was 26%, when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest. When the concentration of carbon dioxide in the mixture was between 10% and 26%, the volume of the light phase was the smallest and the oil displacement effect was the best.展开更多
The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the t...The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the tunnel has a new smoke exhaust system that combines a horizontal smoke exhaust cross section at the top and sidewall smoke exhaust holes.In order to evaluate the potential fire hazards of this type of tunnel,a 1:30 tunnel model was established and 140 smallscale experiments on underwater tunnel fires were conducted.By changing the fire power,fire location,and fan operation mode,different scenarios of submarine immersed tunnel fire were simulated and the related key parameters such as fire smoke diffusion behavior and smoke temperature distribution were studied.On this basis,the optimal smoke control strategy was proposed for different fire scenarios.The research results indicate that the new smoke exhaust system can fully utilize the smoke flow characteristics,significantly improve smoke exhaust efficiency,and increase available evacuation time,thus further enhancing the fire safety of super large cross-section subsea tunnels.展开更多
With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as ...With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low cost.In order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be studied.In this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are provided.Based on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating wire.During the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam.The stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks being.The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas extraction.Under the influence of ground stress,the crack propagation in coal seam will be restrained.The difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced cracks.The permeability enhancement effect of CSW is affected by the breakage degree of coal seam.The shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability enhancement.When arranging two adjacent boreholes for CSW permeability enhancement test,the spacing of boreholes should not be too close,which may lead to negative pressure mutual pulling in the early stage of drainage.At present,the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.展开更多
[Objectives]To determine the optimal reflux extraction process conditions for Compound Coptis Ointment.[Methods]The study employed the orthogonal experimental design method and drug-sensitive disc agar diffusion metho...[Objectives]To determine the optimal reflux extraction process conditions for Compound Coptis Ointment.[Methods]The study employed the orthogonal experimental design method and drug-sensitive disc agar diffusion method to evaluate the extraction rate,berberine hydrochloride content,and bacteriostatic ring diameter of the extract as comprehensive indices,and optimized the extraction process conditions of Compound Coptis Ointment using ethanol reflux.[Results]Based on the results of comprehensive indices,the optimal reflux extraction conditions for Compound Coptis Ointment were determined to be soaking in 1.5 times the amount of 70%ethanol for 2 h,followed by two extractions with 6 times the amount of 70%ethanol for 1 h each time.Three verification tests were conducted under the optimal process conditions.The yield of the extract was 28.32%±0.53%,the content of berberine hydrochloride was 4.68%±0.45%,and the diameter of the bacteriostatic ring was(2.5±0.2)cm.[Conclusions]The extract had higher drug content and exhibited better antibacterial effects.The optimized extraction process is simple,stable,and reliable,and can be effectively used to optimize the extraction process of Compound Coptis Ointment.展开更多
Aim: To determine the predictive value of the hypo-osmotic swelling (HOS) test to identify viable, non-motile sperm. Methods: Semen samples from 20 men with severe asthenozoospermia underwent traditional seminal analy...Aim: To determine the predictive value of the hypo-osmotic swelling (HOS) test to identify viable, non-motile sperm. Methods: Semen samples from 20 men with severe asthenozoospermia underwent traditional seminal analysis, eosin-nigrosin (EN) staining and the HOS test. A further EN stain was then performed on a HOS pre-treated aliquot and a total of 2000 further sperm examined. Results: The median sperm density was 5.1 million/mL (IQR 4.3-13.1) and the median motility was 3.0 % (IQR 0-7). Seven samples showed complete asthenozoospermia. Initial EN staining showed 59 % viability (range 48-69) despite the poor standard parameters and 47 % (range 33-61) in the complete asthenozoospermia subgroup. The HOS test showed 49.9 % reacted overall (range 40-59) and 41.7 % (range 22-61) in the complete asthenozoospermia subgroup. The combined HOS/EN stain showed the positive predictive value of the HOS test to identify viable sperm was 84.2 % overall and 79.7 % in the complete asthenozoospermia subgroup. Conclusion: The HOS test can effectively predict sperm viability in patients with severe and complete asthenozoospermia.展开更多
To solve the problems of low precision of weak feature extraction,heavy reliance on labor and low efficiency of weak feature extraction in X-ray weld detection image of ultra-high voltage(UHV)equipment key parts,an au...To solve the problems of low precision of weak feature extraction,heavy reliance on labor and low efficiency of weak feature extraction in X-ray weld detection image of ultra-high voltage(UHV)equipment key parts,an automatic feature extraction algorithm is proposed.Firstly,the original weld image is denoised while retaining the characteristic information of weak defects by the proposed monostable stochastic resonance method.Then,binarization is achieved by combining Laplacian edge detection and Otsu threshold segmentation.Finally,the automatic identification of weld defect area is realized based on the sequential traversal of binary tree.Several characteristic analysis dimensions are established for weld defects of UHV key parts,including defect area,perimeter,slenderness ratio,duty cycle,etc.The experiment using theweld detection image of the actual production site shows that the proposedmethod can effectively extract theweak feature information ofweld defects and further provide reference for decision-making.展开更多
[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the op...[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.展开更多
With quercetin content and yield of dry extract as investigation indices, three factors, amount of water added, decoction time and decoction times were investigated by an orthogonal test, so as to select the optimal w...With quercetin content and yield of dry extract as investigation indices, three factors, amount of water added, decoction time and decoction times were investigated by an orthogonal test, so as to select the optimal water extraction process for Zihua Qinghuo Capsule. The determined extraction process was adding 8 times of water in five herbs including Viola philippica and decocting for 2 times, 1.5 h each time. Pilot scale test demonstrated that the selected process is stable and feasible, and could provide reliable reference for practical production.展开更多
The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational i...The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational instability may occur for high vertical resolution versions if the stratification parameter C0 taken as a constant. In this paper, the possible cause leading to the instability is discussed and an improved scheme presented where C0 is generalized to be a function of both height and latitudes. Hence the reference atmosphere gets closer to the real atmosphere and the temperature deviation field to be expanded becomes smoother everywhere. Test by real case forecasts shows good computational stability of the new scheme and better prediction performance than-usual schemes of spectral model.展开更多
Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from ...Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.展开更多
[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal do...[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.展开更多
[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the co...[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 (5 μm,4.6 mm × 150 mm) column separation;the mobile phase was acetonitrile-2%H3PO4 (90:10);the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows:ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1:25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.展开更多
[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oi...[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oil was extracted using supercritical CO2 (SC-CO2). The effects of extraction time, temperature and pressure were investigated by single-factor experiments and orthogonal array testing (ORT). The chemical compositions of extracted perilla seed oil were investigated by GC-MS. [Result] The optimal conditions for the extraction of perilla seed oil using SC-CO2 were extraction time of 4 h, extraction temperature at 40 ℃, and extraction pressure at 23 MPa. Under these conditions, the extraction yield of perilla seed oil was maximized to 12.43%. GC-MS analysis revealed that perilla seed oil was a complex mixture containing 76.183% α-linolenic acid. [Conclusion] Supercritical CO2 extraction was proven to be an effective technology to extract oil from perilla seed, and GCMS was also a satisfactory method for analyzing the compositions of perilla seed oil.展开更多
Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction paramet...Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.展开更多
The separation of the by-product (The volume fraction of 3-picoline is 68.472 2% and 4-picoline 26. 517 6% .) in the synthesis of pyridine by dissociation extraction wasstudied. Six separation conditions of the dissoc...The separation of the by-product (The volume fraction of 3-picoline is 68.472 2% and 4-picoline 26. 517 6% .) in the synthesis of pyridine by dissociation extraction wasstudied. Six separation conditions of the dissociation extraction-the kind and the dosage ofextractant and organic solvent, the concentration of the extractant and separation temperature-wereinvestigated. Different levels of each factor were chosen to form an orthogonal test of six factorsand five levels. The results show that the volume ratio of 3-picoline and 4-picoline in organicphase is the highest when 24 mL picolines are separated at 0 t by 2. 0 mol/L p-toluenesulfonic andn-heptane whose dosages are 40 mL and 48 mL, respectively. The effect of the separation isconsiderably improved with repetition test. This process of dissociation extraction has commendablepotential for industrial exploitation.展开更多
Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant (MSO) were studied in the paper. The pilot test results showed that the percentage extractions are more than 9...Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant (MSO) were studied in the paper. The pilot test results showed that the percentage extractions are more than 99% for platinum and palladium in Pt-Pd feed, and the percentage strippings are 100% and 99.2% with HCl and ammonia, respectively. The ratio of palladium to platinum is 0.0016 in stripping platinum solution, and the ratio of platinum to palladium is 0.0020 in stripping palladium solution. The percentage extraction of platinum is 99% in Pt-Rh feed, and the percentage stripping is 100%. The ratio of rhodium to platinum is 0.0002 in stripping platinum solution. Therefore, platinum, palladium, and rhodium feeds are separated effectively with MSO.展开更多
A suction caisson can be extracted by applying reverse pumping water,which cannot be regarded as the reverse process of installation because of the dramatically different soil−structure interaction behavior.Model test...A suction caisson can be extracted by applying reverse pumping water,which cannot be regarded as the reverse process of installation because of the dramatically different soil−structure interaction behavior.Model tests were first carried out in this study to investigate the extraction behavior of the modified suction caisson(MSC)and the regular suction caisson(RSC)in sand by reverse pumping water.The effects of the installation ways(suction-assisted or jacking installation)and the reverse pumping rate on the variations of the over-pressure resulting form reverse pumping water were investigated.It was found that neither the RSC nor the MSC can be fully extracted from sand.When the maximum extraction displacement is obtained,the hydraulic gradient of the sand in the suction caisson reaches the critical value,leading to seepage failure.In addition,the maximum extraction displacement decreases with the increasing reverse pumping rate.Under the same reverse pumping rate,the final extraction displacements for the RSC and MSC installed by suction are lower than those for the RSC and MSC installed by jacking.The final extraction displacement of MSC is almost equal to that of the RSC with the same internal compartment length.Based on the force equilibrium,a method of estimating the maximum extraction displacement is proposed.It has been proved that the proposed method can rationally predict the maximum extraction displacement and the corresponding over-pressure.展开更多
Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertiliz...Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.展开更多
We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residu...We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residues were compared by scanning electron microscopy,and then the activity of LMIC on Lymantria dispar(Asian gypsy moths)larvae was determined.Results showed that the optimal condition of UE was followed by 80 min of extraction time,60%of ethanol concentration and 80 mL g^-1 of liquid–solid ratio.The surface morphologies of UE residue were looser and rougher than ME residue.The corrected mortalities of LMIC on L.dispar larvae was 59.77%.This result indicated that L.mokusin was a good candidate as pesticide for pest management.展开更多
[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,...[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,and liquid ratio on the extraction rate of polysaccharides from chrysanthemum were studied.The optimum operation condition by microwave extraction method was determined and was compared with that by traditional extraction method.[Result] The optimum extraction conditions were:800 W,1:15(solid-liquid ratio),and 15 min.The polysaccharides extraction yield under such optimum condition was 5.59%.The extraction yield of impregnation was generally about 2.73%.[Conclusion] Compared with the traditional extraction method,the microwave extraction was simple,convenient,energy saving,and efficient,and was suitable for industrial extraction of polysaccharide.展开更多
文摘The mass transfer between heavy oil and liquid carbon dioxide and the changes of the heavy phase(mixture of heavy oil and CO_2) and light phase(pure CO_2) in the mixture were tested in lab with heavy oil samples from Russia. The experimental results showed that the heavy oil hardly expanded when the concentration of carbon dioxide in the mixture was 10%. When the concentration of carbon dioxide was higher than 26%, the volume of the heavy phase decreased, and the viscosity of the heavy phase increased exponentially as the light components extracted from the heavy oil exceeded the carbon dioxide saturated in the heavy oil. When the concentration of carbon dioxide in the mixture was 26%, the effect of viscosity reducing to the heavy phase was the strongest. The density of the light and heavy phases, volume factor, and solubility of gas and flash viscosity of heavy phase all increased with the rise of carbon dioxide concentration in the mixture. The best concentration of carbon dioxide in the mixture was 26%, when the heavy oil expanded the most and the viscosity of the heavy phase was the lowest. When the concentration of carbon dioxide in the mixture was between 10% and 26%, the volume of the light phase was the smallest and the oil displacement effect was the best.
基金National Natural Science Foundation of China,Grant/Award Numbers:72091512,52104198,52374210。
文摘The Shenzhen–Zhongshan Bridge is a 24‐km‐long bridge and tunnel system,including a 6.8-km-long super cross section subsea tunnel.To solve the smoke exhaust problem of a super large cross-section subsea tunnel,the tunnel has a new smoke exhaust system that combines a horizontal smoke exhaust cross section at the top and sidewall smoke exhaust holes.In order to evaluate the potential fire hazards of this type of tunnel,a 1:30 tunnel model was established and 140 smallscale experiments on underwater tunnel fires were conducted.By changing the fire power,fire location,and fan operation mode,different scenarios of submarine immersed tunnel fire were simulated and the related key parameters such as fire smoke diffusion behavior and smoke temperature distribution were studied.On this basis,the optimal smoke control strategy was proposed for different fire scenarios.The research results indicate that the new smoke exhaust system can fully utilize the smoke flow characteristics,significantly improve smoke exhaust efficiency,and increase available evacuation time,thus further enhancing the fire safety of super large cross-section subsea tunnels.
基金National Natural Science Foundation of China(52004117,52174117 and 52074146)Postdoctoral Science Foundation of China(2021T140290 and 2020M680975)Basic scientific research project of Liaoning Provincial Department of Education(JYTZD2023073).
文摘With the continuous increase of mining in depth,the gas extraction faces the challenges of low permeability,great ground stress,high temperature and large gas pressure in coal seam.The controllable shock wave(CSW),as a new method for enhancing permeability of coal seam to improve gas extraction,features in the advantages of high efficiency,eco-friendly,and low cost.In order to better utilize the CSW into gas extraction in coal mine,the mechanism and feasibility of CSW enhanced extraction need to be studied.In this paper,the basic principles,the experimental tests,the mathematical models,and the on-site tests of CSW fracturing coal seams are reviewed,thereby its future research directions are provided.Based on the different media between electrodes,the CSW can be divided into three categories:hydraulic effect,wire explosion and excitation of energetic materials by detonating wire.During the process of propagation and attenuation of the high-energy shock wave in coal,the shock wave and bubble pulsation work together to produce an enhanced permeability effect on the coal seam.The stronger the strength of the CSW is,the more cracks created in the coal is,and the greater the length,width and area of the cracks being.The repeated shock on the coal seam is conducive to the formation of complex network fracture system as well as the reduction of coal seam strength,but excessive shock frequency will also damage the coal structure,resulting in the limited effect of the enhanced gas extraction.Under the influence of ground stress,the crack propagation in coal seam will be restrained.The difference of horizontal principal stress has a significant impact on the shape,propagation direction and connectivity of the CSW induced cracks.The permeability enhancement effect of CSW is affected by the breakage degree of coal seam.The shock wave is absorbed by the broken coal,which may hinder the propagation of CSW,resulting in a poor effect of permeability enhancement.When arranging two adjacent boreholes for CSW permeability enhancement test,the spacing of boreholes should not be too close,which may lead to negative pressure mutual pulling in the early stage of drainage.At present,the accurate method for effectively predicting the CSW permeability enhanced range should be further investigated.
基金Supported by Key Research Project of Wuhan Municipal Health Commission(WZ21A08).
文摘[Objectives]To determine the optimal reflux extraction process conditions for Compound Coptis Ointment.[Methods]The study employed the orthogonal experimental design method and drug-sensitive disc agar diffusion method to evaluate the extraction rate,berberine hydrochloride content,and bacteriostatic ring diameter of the extract as comprehensive indices,and optimized the extraction process conditions of Compound Coptis Ointment using ethanol reflux.[Results]Based on the results of comprehensive indices,the optimal reflux extraction conditions for Compound Coptis Ointment were determined to be soaking in 1.5 times the amount of 70%ethanol for 2 h,followed by two extractions with 6 times the amount of 70%ethanol for 1 h each time.Three verification tests were conducted under the optimal process conditions.The yield of the extract was 28.32%±0.53%,the content of berberine hydrochloride was 4.68%±0.45%,and the diameter of the bacteriostatic ring was(2.5±0.2)cm.[Conclusions]The extract had higher drug content and exhibited better antibacterial effects.The optimized extraction process is simple,stable,and reliable,and can be effectively used to optimize the extraction process of Compound Coptis Ointment.
文摘Aim: To determine the predictive value of the hypo-osmotic swelling (HOS) test to identify viable, non-motile sperm. Methods: Semen samples from 20 men with severe asthenozoospermia underwent traditional seminal analysis, eosin-nigrosin (EN) staining and the HOS test. A further EN stain was then performed on a HOS pre-treated aliquot and a total of 2000 further sperm examined. Results: The median sperm density was 5.1 million/mL (IQR 4.3-13.1) and the median motility was 3.0 % (IQR 0-7). Seven samples showed complete asthenozoospermia. Initial EN staining showed 59 % viability (range 48-69) despite the poor standard parameters and 47 % (range 33-61) in the complete asthenozoospermia subgroup. The HOS test showed 49.9 % reacted overall (range 40-59) and 41.7 % (range 22-61) in the complete asthenozoospermia subgroup. The combined HOS/EN stain showed the positive predictive value of the HOS test to identify viable sperm was 84.2 % overall and 79.7 % in the complete asthenozoospermia subgroup. Conclusion: The HOS test can effectively predict sperm viability in patients with severe and complete asthenozoospermia.
文摘To solve the problems of low precision of weak feature extraction,heavy reliance on labor and low efficiency of weak feature extraction in X-ray weld detection image of ultra-high voltage(UHV)equipment key parts,an automatic feature extraction algorithm is proposed.Firstly,the original weld image is denoised while retaining the characteristic information of weak defects by the proposed monostable stochastic resonance method.Then,binarization is achieved by combining Laplacian edge detection and Otsu threshold segmentation.Finally,the automatic identification of weld defect area is realized based on the sequential traversal of binary tree.Several characteristic analysis dimensions are established for weld defects of UHV key parts,including defect area,perimeter,slenderness ratio,duty cycle,etc.The experiment using theweld detection image of the actual production site shows that the proposedmethod can effectively extract theweak feature information ofweld defects and further provide reference for decision-making.
基金Supported by Talent Training and Construction Project of Professor Yang Shilin’s Team in 2017(YSL17010)
文摘[Objectives] The study aimed to optimize the extraction process of Prunellae Spica compound to provide an experimental basis for the development and utilization of the compound. [Methods]Through orthogonal test,the optimal extraction process of Prunellae Spica compound was chosen by using the yield of dry paste and ursolic acid content as evaluation indicators. [Results]The optimal extraction process of Prunellae Spica compound is as follows: solvent dosage was 16 times,and extraction frequency was 3 times,while extraction time was 1 h.[Conclusions]The extraction process of Prunellae Spica compound was stable and feasible,and this study can provide a theoretical basis for further preparation of the compound.
基金Supported by Guiyang Science and Technology Planning Project(ZKHT[2017-4]21)
文摘With quercetin content and yield of dry extract as investigation indices, three factors, amount of water added, decoction time and decoction times were investigated by an orthogonal test, so as to select the optimal water extraction process for Zihua Qinghuo Capsule. The determined extraction process was adding 8 times of water in five herbs including Viola philippica and decocting for 2 times, 1.5 h each time. Pilot scale test demonstrated that the selected process is stable and feasible, and could provide reliable reference for practical production.
基金This work has been carried out under the support of the Medium-range Numerical Weather Forecast research project
文摘The introduction of 'hydrostatic extraction' scheme, or 'standard stratification approximation', into spectral model gained some advantages compared with commonly used schemes. However, computational instability may occur for high vertical resolution versions if the stratification parameter C0 taken as a constant. In this paper, the possible cause leading to the instability is discussed and an improved scheme presented where C0 is generalized to be a function of both height and latitudes. Hence the reference atmosphere gets closer to the real atmosphere and the temperature deviation field to be expanded becomes smoother everywhere. Test by real case forecasts shows good computational stability of the new scheme and better prediction performance than-usual schemes of spectral model.
文摘Recently a research team at Ohio University,USA,conducted a unique full-scale feld load test to simulate the aeration pipe installations at a copper extraction mine operated in Chile.The overliner material taken from the mine was used in recreating the in situ conditions.Electric heaters were utilized to raise the temperature inside each pipe to simulate the essential element of the copper extraction process.The maximum vertical deflection reached by the test pipes was close to 20%,when the simulated heap pile height was 80 m.The plastic pipes and the overliner material were also tested in the laboratory.Based on the results,the maximum heap pile fll depth was recommended for the aeration system.The results indicated that the vertical deflection was the primary performance index for the aeration pipes installed in heap piles at mines.Lastly,the pipe made of polypropylene resin was super.
文摘[Objectives]To investigate the acute toxicity and hepatoprotective effect of Jinchuan formula plum wine extract on mice,determine its safety range,and evaluate its hepatoprotective effect.[Methods]The median lethal dose(LD_(50))was determined by acute toxicity test with the toxic reaction and mortality of mice as indexes.Sixty Kunming mice were randomly divided into 6 groups:normal control group,model group(ConA-induced liver injury model),Jinchuan formula plum wine high,medium and low dose groups(1.0,0.5,0.25 g/kg)and silybin group(0.1 g/kg).The levels of ALT,AST,LDH in serum and TG,VLDL in liver were measured.After HE staining,the pathological changes of liver tissue in mice were observed,and the liver protective effect of Jinchuan formula plum wine extract was analyzed and evaluated.[Results]LD_(50)was 11.18 g/kg,and the 95%confidence limit of LD_(50)was 10.31-12.05 g/kg.The high-dose group of Jinchuan formula plum wine extract could significantly reduce the serum ALT and AST activities of ConA-induced liver injury mice(P<0.05).[Conclusions]Jinchuan formula plum wine extract is relatively safe,and also has a protective effect on liver injury.
基金Supported by National Natural Science Foundation of China(30560119)Supported by Natural Science Foundation of Guangxi(0991030)+3 种基金Innovational Plan Project for Guangxi Postgraduate Ed-ucation(2008105930817M46)Project of Science Research Project of Guangxi Education Department([2006]26),Project of Science Research Project of Guangxi Education Department(200708LX180)Scientific Researc-hing fund project of Guangxi University(X081020)Fund Project for Guangxi Young People(0832008)~~
文摘[Objective] The aim was to provide scientific basis for development and utilization of Pinus elliottii Engelm resources.[Method] The extraction process of shikimic acid in Pinus elliottii Engelm was studied,and the content of shikimic acid was determined by HPLC.The HPLC conditions were as follows;Alltima NH2 (5 μm,4.6 mm × 150 mm) column separation;the mobile phase was acetonitrile-2%H3PO4 (90:10);the flowing velocity was 1 ml/min;test wavelength was 213 nm,the width of belt was 16 nm;reference wavelength was 300 nm,the width of belt was 80 nm.[Result] By the single factor and orthogonal tests,the optimum conditions were found as follows:ethanol concentration 60%,extraction temperature 75 ℃,solid-liquid ratio 1:25,extraction time 2.5 h.The extraction rate of shikimic acid was 1.49%.[Conclusion] Shikimic acid in Pinus elliottii Engelm could be used as a new resource to develop and utilize.
基金Supported by Undergraduate Innovation Training Program of Jiangsu Province(201610327010Z)~~
文摘[Objective] This study was aimed to determine the optimal parameters for the extraction of perilla seed oil to obtain high-quality perilla seed oil and analyze its compositions. [Method] In this study, perilla seed oil was extracted using supercritical CO2 (SC-CO2). The effects of extraction time, temperature and pressure were investigated by single-factor experiments and orthogonal array testing (ORT). The chemical compositions of extracted perilla seed oil were investigated by GC-MS. [Result] The optimal conditions for the extraction of perilla seed oil using SC-CO2 were extraction time of 4 h, extraction temperature at 40 ℃, and extraction pressure at 23 MPa. Under these conditions, the extraction yield of perilla seed oil was maximized to 12.43%. GC-MS analysis revealed that perilla seed oil was a complex mixture containing 76.183% α-linolenic acid. [Conclusion] Supercritical CO2 extraction was proven to be an effective technology to extract oil from perilla seed, and GCMS was also a satisfactory method for analyzing the compositions of perilla seed oil.
基金in part supported by the Forestry Bureau of the Republic of China(Taiwan)(NO.99-06-5-02)
文摘Objective: To investigate suitable condition for extraction of the active components from Ajuga nipponensis(A. nipponensis). Methods: Orthogonal experimental design was used to determine the optimal extraction parameters for ecdysterones and flavonoids. Finally, the hepatoprotective abilities of A. nipponensis extracts were evaluated by CCl_4-induced animal models. Results:Maximum yields of flavonoids(7.87±0.10) mg/g and ecdysterones(0.73±0.02) mg/g could be obtained when the extraction time was 50 min, the extraction temperature was 60 ℃, and the ratio of sample to 70%(v/v) ethanol was 1:20(w/w). The antioxidant property of A. nipponensis was correlated to the concentration of its extracts. At 5 mg/m L, A. nipponensisextract scavenged 84.8% of DPPH radical and had absorbance values of 2.43±0.04 reducing power. Upon CCl_4-induced liver injury, glutamic oxaloacetic transaminase and glutamic pyruvic transaminase decreased significantly after the mice were treated with A. nipponensis. Histological researches also explained that A. nipponensis reduced the extent of liver lesions induced by CCl_4. Conclusions: A. nipponensis exhibited potent antioxidant activity in chemical experimental models and hepatoprotective effect against CCl_4-induced liver damage.
文摘The separation of the by-product (The volume fraction of 3-picoline is 68.472 2% and 4-picoline 26. 517 6% .) in the synthesis of pyridine by dissociation extraction wasstudied. Six separation conditions of the dissociation extraction-the kind and the dosage ofextractant and organic solvent, the concentration of the extractant and separation temperature-wereinvestigated. Different levels of each factor were chosen to form an orthogonal test of six factorsand five levels. The results show that the volume ratio of 3-picoline and 4-picoline in organicphase is the highest when 24 mL picolines are separated at 0 t by 2. 0 mol/L p-toluenesulfonic andn-heptane whose dosages are 40 mL and 48 mL, respectively. The effect of the separation isconsiderably improved with repetition test. This process of dissociation extraction has commendablepotential for industrial exploitation.
文摘Platinum, palladium and rhodium of the raw feeds extracted and separated with a new sulfoxide extractant (MSO) were studied in the paper. The pilot test results showed that the percentage extractions are more than 99% for platinum and palladium in Pt-Pd feed, and the percentage strippings are 100% and 99.2% with HCl and ammonia, respectively. The ratio of palladium to platinum is 0.0016 in stripping platinum solution, and the ratio of platinum to palladium is 0.0020 in stripping palladium solution. The percentage extraction of platinum is 99% in Pt-Rh feed, and the percentage stripping is 100%. The ratio of rhodium to platinum is 0.0002 in stripping platinum solution. Therefore, platinum, palladium, and rhodium feeds are separated effectively with MSO.
基金This study was financially supported by the National Natural Science Foundation of China(Grant Nos.51879044 and 51639002)the Shandong Natural Fund(Grant No.ZR2019BEE007)+1 种基金SDUST Research Fund(Grant No.2015TDJH104)the Project oce and Technology Program(Grant No.J18KA184).
文摘A suction caisson can be extracted by applying reverse pumping water,which cannot be regarded as the reverse process of installation because of the dramatically different soil−structure interaction behavior.Model tests were first carried out in this study to investigate the extraction behavior of the modified suction caisson(MSC)and the regular suction caisson(RSC)in sand by reverse pumping water.The effects of the installation ways(suction-assisted or jacking installation)and the reverse pumping rate on the variations of the over-pressure resulting form reverse pumping water were investigated.It was found that neither the RSC nor the MSC can be fully extracted from sand.When the maximum extraction displacement is obtained,the hydraulic gradient of the sand in the suction caisson reaches the critical value,leading to seepage failure.In addition,the maximum extraction displacement decreases with the increasing reverse pumping rate.Under the same reverse pumping rate,the final extraction displacements for the RSC and MSC installed by suction are lower than those for the RSC and MSC installed by jacking.The final extraction displacement of MSC is almost equal to that of the RSC with the same internal compartment length.Based on the force equilibrium,a method of estimating the maximum extraction displacement is proposed.It has been proved that the proposed method can rationally predict the maximum extraction displacement and the corresponding over-pressure.
文摘Soil test for availability of nutrients and heavy metals is extensively served as a means for the evaluations of soil fertility, and environmental effects and phytotoxicity of pollutants in soils, and for the fertilizer recommendation in agricultural and environmental sciences. Therefore, great attention has been paid to the measurement of elemental availability in soil test.
基金The work was supported by the Central University Fundamental Research Funds Special Fund Project[2572016AA03,25720171118]Harbin Applied Technology Research and Development Project[2016RAXXJ035]the Central Financial Forest Science and Technology Promotion Demonstration Fund Project[JLT[2016]13].
文摘We optimized the extraction process of Lysurus mokusin(L.)Fr.insecticidal compound(LMIC)using response surface methodology with ultrasonic extraction(UE).The surface morphologies of maceration extract(ME)and UE residues were compared by scanning electron microscopy,and then the activity of LMIC on Lymantria dispar(Asian gypsy moths)larvae was determined.Results showed that the optimal condition of UE was followed by 80 min of extraction time,60%of ethanol concentration and 80 mL g^-1 of liquid–solid ratio.The surface morphologies of UE residue were looser and rougher than ME residue.The corrected mortalities of LMIC on L.dispar larvae was 59.77%.This result indicated that L.mokusin was a good candidate as pesticide for pest management.
基金Supported by Doctoral Initial Funding of Henan University of TCM(BSJJ2009-34)
文摘[Objective] The aim was to study the optimum extraction process of polysaccharide from chrysanthemum.[Method] By dint of orthogonal and single-factor experiments,the influences of microwave efficiency,extraction time,and liquid ratio on the extraction rate of polysaccharides from chrysanthemum were studied.The optimum operation condition by microwave extraction method was determined and was compared with that by traditional extraction method.[Result] The optimum extraction conditions were:800 W,1:15(solid-liquid ratio),and 15 min.The polysaccharides extraction yield under such optimum condition was 5.59%.The extraction yield of impregnation was generally about 2.73%.[Conclusion] Compared with the traditional extraction method,the microwave extraction was simple,convenient,energy saving,and efficient,and was suitable for industrial extraction of polysaccharide.