Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showe...Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.展开更多
Thermodynamic analysis was applied to study combined partial oxidation and carbon dioxide reforming of methane in view of carbon formation. The equilibrium calculations employing the Gibbs energy minimization were per...Thermodynamic analysis was applied to study combined partial oxidation and carbon dioxide reforming of methane in view of carbon formation. The equilibrium calculations employing the Gibbs energy minimization were performed upon wide ranges of pressure （1-25 atm）, temperature （600-1300 K）, carbon dioxide to methane ratio （0-2） and oxygen to methane ratio （0-1）. The thermodynamic results were compared with the results obtained over a Ru supported catalyst. The results revealed that by increasing the reaction pressure methane conversion decreased. Also it was found that the atmospheric pressure is the preferable pressure for both dry reforming and partial oxidation of methane and increasing the temperature caused increases in both activity of carbon and conversion of methane. The results clearly showed that the addition of O2 to the feed mixture could lead to a reduction of carbon deposition.展开更多
Inflammatory bowel disease(IBD),encompassing Crohn’s disease and ulcerative colitis,manifests as a chronic,recurrent,and refractory intestinal inflammatory condition significantly impacting patients’quality of life....Inflammatory bowel disease(IBD),encompassing Crohn’s disease and ulcerative colitis,manifests as a chronic,recurrent,and refractory intestinal inflammatory condition significantly impacting patients’quality of life.Despite ongoing research,its etiology and pathogenesis remain incompletely understood.Recent advancements in medical research highlight the critical role of drug combination therapies in managing IBD.This paper employs the strengths,weaknesses,opportunities,and threats framework to evaluate the four strategic elements(strengths,weaknesses,opportunities,and threats)pertaining to combination therapies for IBD.Among the strengths,the paper underscores the efficacy of multi-targeted strategies,the advancement of personalized medicine,and the mitigation of drug resistance.Nonetheless,the analysis identifies significant weaknesses,including the prohibitive cost of treatment,issues with patient compliance,and the necessity for comprehensive long-term safety data.The paper also delineates opportunities to augment therapeutic success through the incorporation of biomarkers,the application of artificial intelligence,and extensive international collaborative efforts.In contrast,the paper does not shy away from addressing the threats,which include the potential for therapeutic resistance and the logistical challenges inherent in global therapy deployment.These initiatives aim to refine future therapeutic practices,fostering safer,more effective,and personalized treatment paradigms for IBD patients.展开更多
Current research and ways of capturing mechanical energy are discussed in this paper. By the aid of the comprehensive thermodynamic analysis and Aspen simulation tool, the amount of a vailable work that can be produc...Current research and ways of capturing mechanical energy are discussed in this paper. By the aid of the comprehensive thermodynamic analysis and Aspen simulation tool, the amount of a vailable work that can be produced from capturing the pressure energy has been calculated. Based on the comprehensive thermodynamic analysis, two systems have been proposed to capture pressure energy of natural gas to generate electricity. In this study, the expression of exergy is given which can be used in evaluating purposes. A problem with this multidisciplinary study is the complicated boundary condition. In conclusion, a technical prospect on recoverable natural gas pressure energy has been presented based on total energy system theory.展开更多
For the requirement of safe and stable operation,the combined sealing structure was used for reciprocating motion in the deep sea high-pressure environment,and the effects of different seawater depths and shaft moveme...For the requirement of safe and stable operation,the combined sealing structure was used for reciprocating motion in the deep sea high-pressure environment,and the effects of different seawater depths and shaft movement speed on the sealing performance of the combined sealing structure were studied.The change rule of the sealing performance of the combined sealing structure of reciprocating motion under different working conditions is proved.The study shows that in the combined sealing structure of reciprocating movement,the Von Mises stress and the contact stress of the O-ring varies with the direction of the shaft movement.The Von Mises stress and contact stress of the O-ring,the Von Mises stress and the contact stress on each sealing lip of the slip ring gradually increase with the increasing of seawater depths.At the same time,the Von Mises stress of the O-ring which in the process of the shaft upward movement is greater than the shaft downward movement,making the shaft upward movement more likely to cause the O-ring relaxation and fatigue.The shaft movement speed has no significant influence on the Von Mises stress and contact stress of the O-ring.The research results provide theoretical guidance and technical support for the selection and optimization of the geometrical parameters of the combined sealing structure in the deep-sea high-pressure environment.展开更多
Diffusions of multiple components have numerous applications such as underground water flow, pollutant movement, stratospheric warming, and food processing. Particularly, liquid hydrogen is used in the cooling process...Diffusions of multiple components have numerous applications such as underground water flow, pollutant movement, stratospheric warming, and food processing. Particularly, liquid hydrogen is used in the cooling process of the aeroplane. Further, liquid nitrogen can find applications in cooling equipment or electronic devices, i.e., high temperature superconducting(HTS) cables. So, herein, we have analysed the entropy generation(EG), nonlinear thermal radiation and unsteady(time-dependent) nature of the flow on quadratic combined convective flow over a permeable slender cylinder with diffusions of liquid hydrogen and nitrogen. The governing equations for flow and heat transfer characteristics are expressed in terms of nonlinear coupled partial differential equations. The solutions of these equations are attempted numerically by employing the quasilinearization technique with the implicit finite difference approximation. It is found that EG is minimum for double diffusion(liquid hydrogen and heat diffusion)than triple diffusion(diffusion of liquid hydrogen, nitrogen and heat). The enhancing values of the radiation parameter R_(d) and temperature ratio θ_(w) augment the fluid temperature for steady and unsteady cases as well as the local Nusselt number. Because, the fluid absorbs the heat energy released due to radiation, and in turn releases the heat energy from the cylinder to the surrounding surface.展开更多
This paper investigates Q420 dual-angle cross combined section columns under axial and eccentric compression by conducting experiments.The specimen parameters,experimental setup,and test results are presented.It showe...This paper investigates Q420 dual-angle cross combined section columns under axial and eccentric compression by conducting experiments.The specimen parameters,experimental setup,and test results are presented.It showed that local buckling occurred apparently for single internode specimens(λ<35)under axial compression,while overall bending buckling appeared for others,and no torsional buckling occurred.The theoretical formulas on stability factor were derived by the energy approach.Non-linear finite element models considering residual stress were established using ANSYS which were verified by the corresponding experimental results.The parametric study was to evaluate the effects of slenderness ratio(λ),width to thickness ratio of angles(b/t),the number of filled plate(n),load relative eccentricity(e)and the lateral support stiffness on the ultimate strengths of dual-angle cross combined section columns.Based on above analysis,the design equations are proposed by using curve fitting technique.It is shown from comparison between test results,finite element analysis and related specifications that the ultimate strength from theoretical formulas,proposed equations and finite element models are consistent with experiments results.展开更多
The finite element analysis was carried out for a composite vertical axis wind turbine with lift-drag combined starting structures to ensure the structure safety of a vertical axis wind turbine(VAWT).The static and mo...The finite element analysis was carried out for a composite vertical axis wind turbine with lift-drag combined starting structures to ensure the structure safety of a vertical axis wind turbine(VAWT).The static and modal analysis of rotor of a composite vertical axis wind turbine was conducted by using ANSYS software.The relevant contour sketch of stress and deformation was obtained.The analysis was made for static structural mechanics,modal analysis of rotor and the total deformation and vibration profile to evaluate the influence on the working capability of the rotor.The analysis results show that the various structure parameters lie in the safety range of structural mechanics in the relative standards.The analysis showing the design safe to operate the rotor of a vertical axis wind turbine.The methods used in this study can be used as a good reference for the structural mechanics′analysis of VAWTs.展开更多
Objective: To analyze the non-periodic, unstable and even chaotic echoes scattered from microbubbles which are extremely sensitive and may easily collapse, fragment or shrink when ultrasound contrast agents are expose...Objective: To analyze the non-periodic, unstable and even chaotic echoes scattered from microbubbles which are extremely sensitive and may easily collapse, fragment or shrink when ultrasound contrast agents are exposed to ultrasound (US) irradiation. Methods: The combined time-frequency analysis was applied to the original signals instead of the traditional Fourier spectral analysis technique. Results: The results obtained from simulation as well as experiment showed that the subharmonic, 2nd harmonic and ultra harmonic of the microbubbles occurred during the oscillation and varied with time. The dependence on the incident ultrasonic amplitude and microbubble parameters were established. Conclusion: The transient echoes backscattered from the ultrasound agent in the evaluation of the blood perfusion can be analyzed thoroughly by the technique of combined-frequency analysis and the time detail of the frequency contents can be revealed.展开更多
Objective:To systematically evaluate the clinical effect (including effective rate and recurrence rate) of the combination of traditional Chinese and Western medicine in the treatment of granulomatous mastitis (GM).Me...Objective:To systematically evaluate the clinical effect (including effective rate and recurrence rate) of the combination of traditional Chinese and Western medicine in the treatment of granulomatous mastitis (GM).Methods: Computer searches CNKI, Wanfang database, VIP, PubMed, web of science and EMBASE, Chinese biomedical database, and selects randomized controlled trial (RCT) of treating granulomatous mastitis with the combination of traditional Chinese and Western medicine. The retrieval time is from July 2019 to July 2019. Then, we used Revman 5.3 software to meta analyze the data.Results: Nine RCTs were included, six of which were effective observation, two of which were recurrence rate observation, one of which was effective observation and reexamination rate observation. A total of 664 patients were included, including 456 in the experimental group and 208 in the control group. After analysis, it was found that the effective rate of GM in the experimental group was 92.3%, which was significantly higher than that in the control group (Western medicine alone) by 75.5% (or = 4.09, 95% CI (2.28, 7.36), P < 00001), the recurrence rate of GM in the experimental group (treated with integrated traditional Chinese and Western Medicine) was 21.6%, which was significantly lower than that in the control group (treated with western medicine alone) by 55.7% (or = 0.19, 95% CI (0.10, 0.37), P < 0.0001).Conclusion: The combination of traditional Chinese and Western medicine in the treatment of granulomatous mastitis can not only improve the effective rate of clinical treatment, but also reduce the recurrence rate of granulomatous mastitis.展开更多
In this paper, the relationships between the region of the two coexisting kinds of macro-defects and the reduction in area, as well as between the region and the relative residual thickness of the billet are studied f...In this paper, the relationships between the region of the two coexisting kinds of macro-defects and the reduction in area, as well as between the region and the relative residual thickness of the billet are studied for the cup-cup axisymmetric combined extrusion, on the basis of the analytical expression obtained by the upper-bound approach. The presented model and conclusions are confirmed by the experimental results in this paper.展开更多
The present paper is addressed to the finite element method combined with dynamic photoelastic analysis of propagating cracks, that is, on the basis of [1] by Chien Wei-zang, finite elements which incorporate the prop...The present paper is addressed to the finite element method combined with dynamic photoelastic analysis of propagating cracks, that is, on the basis of [1] by Chien Wei-zang, finite elements which incorporate the propagating crack-tip singularity intrinsic to two-dimensional elasticity are employed. THe relation between crack opening length and time step obtained from dynamic photoelaslie analysis is used as a definite condition for solving the dynamic equations and simulating the crack propagations as well As an example, the impact response of dynamie-bending-test specimen is investigated and the dynamic stress-intensity factor obtained from the mentioned finite element analysis and dynamic photoelasticity is in reasonable agreement with each other.展开更多
Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance pr...Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.展开更多
In this paper, the kinematically admissible velocity field with surface crack on forward extruding bar is put forward during the axisymmetric cup-bar combined extrusion process, in accordance with the results of model...In this paper, the kinematically admissible velocity field with surface crack on forward extruding bar is put forward during the axisymmetric cup-bar combined extrusion process, in accordance with the results of model experiments.On the basis of velocity field, the necessary condition for surface crack formation on the forward extruding bar is derived, with the help of upper bound theorem and the minimum energy principle. Meanwhile, the relationships between surface crack formation and combination of reduction in area for the part of forward and backward extursions relative residual thickness of billet (T/R0),frictional factor (m) or relative land length of ram and chamber are calculated during the extrusion process. Therefore, whether the surface crack on forward exturding bar occurs can be predicted before extruding the lower-plasticity metals for axisymmetric cup-bar combined extrusion process.The analytical results agree very well with experimental results of aluminium alloy LY12 (ASTM 2024) and LC4 (ASTM 7075).展开更多
To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zo...To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zone, flow dividing zone, welding chamber, and sizing zone, and the corresponding stress formulae in various zones were established using the slab method. The deformation zones of CASTEX groove were divided into liquid and semisolid zone, solid primary gripping zone, and solid gripping zone, and the formulae of pipe extrusion forces were established. Experiments were carried out on the self-designed CASTEX machine to obtain the aluminum pipe and measure its extrusion force using the expansion combination die. The experimental results of radial extrusion force for aluminum pipe are in good agreement with the calculated ones.展开更多
Objective: to observe and analyze the curative effect of traditional Chinese medicine combined with ozone in the treatment of apoplectic hemiplegia sequelae, so as to provide reference for drug treatment of apoplectic...Objective: to observe and analyze the curative effect of traditional Chinese medicine combined with ozone in the treatment of apoplectic hemiplegia sequelae, so as to provide reference for drug treatment of apoplectic hemiplegia patients. Methods: 124 patients with stroke and hemiplegia in the hospital from April 2021 to June 2021 were selected, and the beds were randomly allocated, and were divided into 62 cases of control group and 62 cases of observation group according to whether TCM combined with ozone therapy was carried out. Results: traditional Chinese medicine combined with ozone in the treatment of stroke hemiplegia can effectively avoid the occurrence of sequelae, such as facial paralysis, aphasia and hypoesthesia caused by nerve recession. The time of symptom disappearance is significantly better than that of the control group, and the difference is statistically significant. Conclusion: traditional Chinese medicine combined with ozone in the treatment of stroke hemiplegia can significantly reduce the sequelae symptoms of patients and improve the quality of life of patients.展开更多
Objective: to study the efficacy of passive reduction combined with drugs in the treatment of benign paroxysmal positional vertigo. Methods: 80 patients with benign paroxysmal positional vertigo were selected from Jan...Objective: to study the efficacy of passive reduction combined with drugs in the treatment of benign paroxysmal positional vertigo. Methods: 80 patients with benign paroxysmal positional vertigo were selected from January 2020 to December 2020. The patients were divided into two groups according to different treatment methods. Besstatin mesylate and flunarizine hydrochloride capsule were used in the treatment. The observation group was treated with drugs on the basis of passive reduction. Results: the total effective cure rate of the observation group was 92.5%, the incidence of adverse events was 2.5%, and the recurrence rate after treatment was 17.5%. The total effective treatment rate of the control group was 75%, the incidence of adverse events was 10%, and the recurrence rate was 47.5%. Conclusion: in the treatment of patients with benign paroxytic positional vertigo, passive reduction combined with drugs can improve the treatment effect, reduce the occurrence of side effects, and it is not easy to relapse after treatment.展开更多
Objective To evaluate the long-term therapeutic effect and histologic result of ADM combined with autologous thin split-thickness skin graft.Methods 23 patients were treated with acellalar dermal matrix(ADM) combined ...Objective To evaluate the long-term therapeutic effect and histologic result of ADM combined with autologous thin split-thickness skin graft.Methods 23 patients were treated with acellalar dermal matrix(ADM) combined with autoiogous展开更多
AIM： To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS： We performed a systematic sear...AIM： To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS： We performed a systematic search of the related literature in the Cochrane Library, PubM ed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction（IOPR%） from baseline to end-point, the percentage of number of glaucoma medications reduction from pre-to post-operation, and the secondary efficacy evaluations were performed by odds ratio（OR） and 95% confidence interval（CI） for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using Rev Man software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi^2 test and the I^2 measure.RESULTS： Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification.CONCLUSION： Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.展开更多
文摘Quick, simple to perform, and cheap biomarkers were combined in a rapid assessment approach to measure the effects of metal pollutants, Cu, Cd, Pb and Zn in meadow burozem on wheat. Analysis of orthogonal design showed that the significant zinc factor indicated both the inhibition rate of shoot mass and that of root elongation were affected by zinc(P<0.05 and P<0.01, respectively). The first toxicity canonical variable (TOXI), formed from the toxicity data set, explained 49% of the total variance in the toxicity data set; the first biological canonical variable(BIOL) explained 42% of the total variation in the biological data set. The correlation between the first canonical variables TOXI and BIOL (canonical correlation) was 0.94 (P<0.0001). Therefore, it is reliable and feasible to use the achievement to assess toxicity of heavy metal combined polluted soil using canonical analysis. Toxicity of soil combined polluted by heavy metals to plant community was estimated by comparing the IC 50 values describing the concentration needed to cause 50% decrease with grow rate compared to no metal addition. Environmental quality standard for soils prescribe that all these tested concentration of heavy metals in soil should not cause hazard and pollution ultimately, whereas it indicated that the soils in second grade cause more or less than 50% inhibition rates of wheat growth. So environmental quality standard for soils can be modified to include other features.
基金supported by University of Kashan(Grant No.158426/5)
文摘Thermodynamic analysis was applied to study combined partial oxidation and carbon dioxide reforming of methane in view of carbon formation. The equilibrium calculations employing the Gibbs energy minimization were performed upon wide ranges of pressure （1-25 atm）, temperature （600-1300 K）, carbon dioxide to methane ratio （0-2） and oxygen to methane ratio （0-1）. The thermodynamic results were compared with the results obtained over a Ru supported catalyst. The results revealed that by increasing the reaction pressure methane conversion decreased. Also it was found that the atmospheric pressure is the preferable pressure for both dry reforming and partial oxidation of methane and increasing the temperature caused increases in both activity of carbon and conversion of methane. The results clearly showed that the addition of O2 to the feed mixture could lead to a reduction of carbon deposition.
文摘Inflammatory bowel disease(IBD),encompassing Crohn’s disease and ulcerative colitis,manifests as a chronic,recurrent,and refractory intestinal inflammatory condition significantly impacting patients’quality of life.Despite ongoing research,its etiology and pathogenesis remain incompletely understood.Recent advancements in medical research highlight the critical role of drug combination therapies in managing IBD.This paper employs the strengths,weaknesses,opportunities,and threats framework to evaluate the four strategic elements(strengths,weaknesses,opportunities,and threats)pertaining to combination therapies for IBD.Among the strengths,the paper underscores the efficacy of multi-targeted strategies,the advancement of personalized medicine,and the mitigation of drug resistance.Nonetheless,the analysis identifies significant weaknesses,including the prohibitive cost of treatment,issues with patient compliance,and the necessity for comprehensive long-term safety data.The paper also delineates opportunities to augment therapeutic success through the incorporation of biomarkers,the application of artificial intelligence,and extensive international collaborative efforts.In contrast,the paper does not shy away from addressing the threats,which include the potential for therapeutic resistance and the logistical challenges inherent in global therapy deployment.These initiatives aim to refine future therapeutic practices,fostering safer,more effective,and personalized treatment paradigms for IBD patients.
基金Supported by Tianjin Institute of Urban Construction(03046)
文摘Current research and ways of capturing mechanical energy are discussed in this paper. By the aid of the comprehensive thermodynamic analysis and Aspen simulation tool, the amount of a vailable work that can be produced from capturing the pressure energy has been calculated. Based on the comprehensive thermodynamic analysis, two systems have been proposed to capture pressure energy of natural gas to generate electricity. In this study, the expression of exergy is given which can be used in evaluating purposes. A problem with this multidisciplinary study is the complicated boundary condition. In conclusion, a technical prospect on recoverable natural gas pressure energy has been presented based on total energy system theory.
基金supported by the National Natural Science Foundation of China (Grant No.51705145, 51779092)the National Key Research and Development Program of China (Grant No.2016YFC0300502 and No.2017YFC0307501)+1 种基金Natural Science Foundation of Hunan Province of China (Grant No.2019JJ50182)Research Foundation of Education Bureau of Hunan Province (Grant No.18B205)
文摘For the requirement of safe and stable operation,the combined sealing structure was used for reciprocating motion in the deep sea high-pressure environment,and the effects of different seawater depths and shaft movement speed on the sealing performance of the combined sealing structure were studied.The change rule of the sealing performance of the combined sealing structure of reciprocating motion under different working conditions is proved.The study shows that in the combined sealing structure of reciprocating movement,the Von Mises stress and the contact stress of the O-ring varies with the direction of the shaft movement.The Von Mises stress and contact stress of the O-ring,the Von Mises stress and the contact stress on each sealing lip of the slip ring gradually increase with the increasing of seawater depths.At the same time,the Von Mises stress of the O-ring which in the process of the shaft upward movement is greater than the shaft downward movement,making the shaft upward movement more likely to cause the O-ring relaxation and fatigue.The shaft movement speed has no significant influence on the Von Mises stress and contact stress of the O-ring.The research results provide theoretical guidance and technical support for the selection and optimization of the geometrical parameters of the combined sealing structure in the deep-sea high-pressure environment.
文摘Diffusions of multiple components have numerous applications such as underground water flow, pollutant movement, stratospheric warming, and food processing. Particularly, liquid hydrogen is used in the cooling process of the aeroplane. Further, liquid nitrogen can find applications in cooling equipment or electronic devices, i.e., high temperature superconducting(HTS) cables. So, herein, we have analysed the entropy generation(EG), nonlinear thermal radiation and unsteady(time-dependent) nature of the flow on quadratic combined convective flow over a permeable slender cylinder with diffusions of liquid hydrogen and nitrogen. The governing equations for flow and heat transfer characteristics are expressed in terms of nonlinear coupled partial differential equations. The solutions of these equations are attempted numerically by employing the quasilinearization technique with the implicit finite difference approximation. It is found that EG is minimum for double diffusion(liquid hydrogen and heat diffusion)than triple diffusion(diffusion of liquid hydrogen, nitrogen and heat). The enhancing values of the radiation parameter R_(d) and temperature ratio θ_(w) augment the fluid temperature for steady and unsteady cases as well as the local Nusselt number. Because, the fluid absorbs the heat energy released due to radiation, and in turn releases the heat energy from the cylinder to the surrounding surface.
文摘This paper investigates Q420 dual-angle cross combined section columns under axial and eccentric compression by conducting experiments.The specimen parameters,experimental setup,and test results are presented.It showed that local buckling occurred apparently for single internode specimens(λ<35)under axial compression,while overall bending buckling appeared for others,and no torsional buckling occurred.The theoretical formulas on stability factor were derived by the energy approach.Non-linear finite element models considering residual stress were established using ANSYS which were verified by the corresponding experimental results.The parametric study was to evaluate the effects of slenderness ratio(λ),width to thickness ratio of angles(b/t),the number of filled plate(n),load relative eccentricity(e)and the lateral support stiffness on the ultimate strengths of dual-angle cross combined section columns.Based on above analysis,the design equations are proposed by using curve fitting technique.It is shown from comparison between test results,finite element analysis and related specifications that the ultimate strength from theoretical formulas,proposed equations and finite element models are consistent with experiments results.
文摘The finite element analysis was carried out for a composite vertical axis wind turbine with lift-drag combined starting structures to ensure the structure safety of a vertical axis wind turbine(VAWT).The static and modal analysis of rotor of a composite vertical axis wind turbine was conducted by using ANSYS software.The relevant contour sketch of stress and deformation was obtained.The analysis was made for static structural mechanics,modal analysis of rotor and the total deformation and vibration profile to evaluate the influence on the working capability of the rotor.The analysis results show that the various structure parameters lie in the safety range of structural mechanics in the relative standards.The analysis showing the design safe to operate the rotor of a vertical axis wind turbine.The methods used in this study can be used as a good reference for the structural mechanics′analysis of VAWTs.
文摘Objective: To analyze the non-periodic, unstable and even chaotic echoes scattered from microbubbles which are extremely sensitive and may easily collapse, fragment or shrink when ultrasound contrast agents are exposed to ultrasound (US) irradiation. Methods: The combined time-frequency analysis was applied to the original signals instead of the traditional Fourier spectral analysis technique. Results: The results obtained from simulation as well as experiment showed that the subharmonic, 2nd harmonic and ultra harmonic of the microbubbles occurred during the oscillation and varied with time. The dependence on the incident ultrasonic amplitude and microbubble parameters were established. Conclusion: The transient echoes backscattered from the ultrasound agent in the evaluation of the blood perfusion can be analyzed thoroughly by the technique of combined-frequency analysis and the time detail of the frequency contents can be revealed.
基金Shandong Province TCM science and technology development plan project(2019-0159)
文摘Objective:To systematically evaluate the clinical effect (including effective rate and recurrence rate) of the combination of traditional Chinese and Western medicine in the treatment of granulomatous mastitis (GM).Methods: Computer searches CNKI, Wanfang database, VIP, PubMed, web of science and EMBASE, Chinese biomedical database, and selects randomized controlled trial (RCT) of treating granulomatous mastitis with the combination of traditional Chinese and Western medicine. The retrieval time is from July 2019 to July 2019. Then, we used Revman 5.3 software to meta analyze the data.Results: Nine RCTs were included, six of which were effective observation, two of which were recurrence rate observation, one of which was effective observation and reexamination rate observation. A total of 664 patients were included, including 456 in the experimental group and 208 in the control group. After analysis, it was found that the effective rate of GM in the experimental group was 92.3%, which was significantly higher than that in the control group (Western medicine alone) by 75.5% (or = 4.09, 95% CI (2.28, 7.36), P < 00001), the recurrence rate of GM in the experimental group (treated with integrated traditional Chinese and Western Medicine) was 21.6%, which was significantly lower than that in the control group (treated with western medicine alone) by 55.7% (or = 0.19, 95% CI (0.10, 0.37), P < 0.0001).Conclusion: The combination of traditional Chinese and Western medicine in the treatment of granulomatous mastitis can not only improve the effective rate of clinical treatment, but also reduce the recurrence rate of granulomatous mastitis.
文摘In this paper, the relationships between the region of the two coexisting kinds of macro-defects and the reduction in area, as well as between the region and the relative residual thickness of the billet are studied for the cup-cup axisymmetric combined extrusion, on the basis of the analytical expression obtained by the upper-bound approach. The presented model and conclusions are confirmed by the experimental results in this paper.
文摘The present paper is addressed to the finite element method combined with dynamic photoelastic analysis of propagating cracks, that is, on the basis of [1] by Chien Wei-zang, finite elements which incorporate the propagating crack-tip singularity intrinsic to two-dimensional elasticity are employed. THe relation between crack opening length and time step obtained from dynamic photoelaslie analysis is used as a definite condition for solving the dynamic equations and simulating the crack propagations as well As an example, the impact response of dynamie-bending-test specimen is investigated and the dynamic stress-intensity factor obtained from the mentioned finite element analysis and dynamic photoelasticity is in reasonable agreement with each other.
文摘Five phospholipids in human placenta were determined by phosphorus 31 nuclear magnetic resonance(^(31)P NMR)spectroscopy and thin-layer chromatography(TLC) scanning combined with the corrective method of absorbance proportional coefficient. The NMR spectrometer used this investigation was a Bruker AM-500 spectrometer operating at 202.4 MHz for ^(31)P chemical shifts are relative to 85% phosphoric acid. TIC was carried out by silica gel H plate developed in chloroform-methanol-glacial acetic acid-ethanol-water(25:4:6:2:0.5),with Vaskovsky reagent as colour -developing agent of phospholipids.
文摘In this paper, the kinematically admissible velocity field with surface crack on forward extruding bar is put forward during the axisymmetric cup-bar combined extrusion process, in accordance with the results of model experiments.On the basis of velocity field, the necessary condition for surface crack formation on the forward extruding bar is derived, with the help of upper bound theorem and the minimum energy principle. Meanwhile, the relationships between surface crack formation and combination of reduction in area for the part of forward and backward extursions relative residual thickness of billet (T/R0),frictional factor (m) or relative land length of ram and chamber are calculated during the extrusion process. Therefore, whether the surface crack on forward exturding bar occurs can be predicted before extruding the lower-plasticity metals for axisymmetric cup-bar combined extrusion process.The analytical results agree very well with experimental results of aluminium alloy LY12 (ASTM 2024) and LC4 (ASTM 7075).
基金Projects(51334006,50274020)supported by the National Natural Science Foundation of China
文摘To determine the extrusion force of pipe fabricated by continuous casting and extrusion (CASTEX) using an expansion combination die, the metallic expansion combination die was divided into diversion zone, expansion zone, flow dividing zone, welding chamber, and sizing zone, and the corresponding stress formulae in various zones were established using the slab method. The deformation zones of CASTEX groove were divided into liquid and semisolid zone, solid primary gripping zone, and solid gripping zone, and the formulae of pipe extrusion forces were established. Experiments were carried out on the self-designed CASTEX machine to obtain the aluminum pipe and measure its extrusion force using the expansion combination die. The experimental results of radial extrusion force for aluminum pipe are in good agreement with the calculated ones.
文摘Objective: to observe and analyze the curative effect of traditional Chinese medicine combined with ozone in the treatment of apoplectic hemiplegia sequelae, so as to provide reference for drug treatment of apoplectic hemiplegia patients. Methods: 124 patients with stroke and hemiplegia in the hospital from April 2021 to June 2021 were selected, and the beds were randomly allocated, and were divided into 62 cases of control group and 62 cases of observation group according to whether TCM combined with ozone therapy was carried out. Results: traditional Chinese medicine combined with ozone in the treatment of stroke hemiplegia can effectively avoid the occurrence of sequelae, such as facial paralysis, aphasia and hypoesthesia caused by nerve recession. The time of symptom disappearance is significantly better than that of the control group, and the difference is statistically significant. Conclusion: traditional Chinese medicine combined with ozone in the treatment of stroke hemiplegia can significantly reduce the sequelae symptoms of patients and improve the quality of life of patients.
文摘Objective: to study the efficacy of passive reduction combined with drugs in the treatment of benign paroxysmal positional vertigo. Methods: 80 patients with benign paroxysmal positional vertigo were selected from January 2020 to December 2020. The patients were divided into two groups according to different treatment methods. Besstatin mesylate and flunarizine hydrochloride capsule were used in the treatment. The observation group was treated with drugs on the basis of passive reduction. Results: the total effective cure rate of the observation group was 92.5%, the incidence of adverse events was 2.5%, and the recurrence rate after treatment was 17.5%. The total effective treatment rate of the control group was 75%, the incidence of adverse events was 10%, and the recurrence rate was 47.5%. Conclusion: in the treatment of patients with benign paroxytic positional vertigo, passive reduction combined with drugs can improve the treatment effect, reduce the occurrence of side effects, and it is not easy to relapse after treatment.
文摘Objective To evaluate the long-term therapeutic effect and histologic result of ADM combined with autologous thin split-thickness skin graft.Methods 23 patients were treated with acellalar dermal matrix(ADM) combined with autoiogous
基金Supported by National Natural Science Foundation of China(No.8170080No.81470609)the Natural Science Foundation of Shandong Province(No.ZR2017MH008)
文摘AIM： To conduct a systematic review and quantitative Meta-analysis of the efficacy and safety of combined surgery for the eyes with coexisting cataract and open angle glaucoma.METHODS： We performed a systematic search of the related literature in the Cochrane Library, PubM ed, EMBASE, Web of Science databases, CNKI, CBM and Wan Fang databases, with no limitations on language or publication date. The primary efficacy estimate was identified by weighted mean difference of the percentage of intraocular pressure reduction（IOPR%） from baseline to end-point, the percentage of number of glaucoma medications reduction from pre-to post-operation, and the secondary efficacy evaluations were performed by odds ratio（OR） and 95% confidence interval（CI） for complete and qualified success rate. Besides, ORs were applied to assess the tolerability of adverse incidents. Meta-analyses of fixed or random effect models were performed using Rev Man software 5.2 to gather the consequences. Heterogeneity was evaluated by Chi^2 test and the I^2 measure.RESULTS： Ten studies enrolling 3108 patients were included. The combined consequences indicated that both glaucoma and combined cataract and glaucoma surgery significantly decreased IOP. For deep sclerectomy vs deep sclerectomy plus phacoemulsification and canaloplasty vs phaco-canaloplasty, the differences in IOPR% were not all statistically significant while trabeculotomy was detected to gain a quantitatively greater IOPR% compared with trabeculotomy plus phacoemulsification. Furthermore, there was no statistical significance in the complete and qualified success rate, and the rates of adverse incidents for trabeculotomy vs trabeculotomy plus phacoemulsification.CONCLUSION： Compared with trabeculotomy plus phacoemulsification, trabeculectomy alone is more effective in lowering IOP and the number of glaucoma medications, while the two surgeries can not demonstrate statistical differences in the complete success rate, qualified success rate, or incidence of adverse incidents.
