In order to study the effects of wet compression on a transonic compressor,a full 3-D steady numerical simulation was carried out under varying conditions.Different injected water flow rates and droplet diameters were...In order to study the effects of wet compression on a transonic compressor,a full 3-D steady numerical simulation was carried out under varying conditions.Different injected water flow rates and droplet diameters were considered.The effect of wet compression on the shock,separated flow,pressure ratio,and efficiency was investigated.Additionally,the effect of wet compression on the tip clearance when the compressor runs in the near-stall and stall situations was emphasized.Analysis of the results shows that the range of stable operation is extended,and that the pressure ratio and inlet air flow rate are also increased at the near-stall point.In addition,it seems that there is an optimum size of the droplet diameter.展开更多
[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mas...[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mastalgia were selected,and divided into the experimental group and control group( 30 cases for each group). The control group was treated with acupuncture at distal point,and the experimental group was treated with TCM local hot-wet compress therapy combined with acupuncture at distal point. Then,the clinical therapeutic efficacy of two groups was compared. [Results]The experimental group was superior to the control group in relieving the breast pain,improving emotional integral,reducing breast lumps,improving lump texture,and improving TCM syndrome integral( P < 0. 05). [Conclusions]The digestion ointment prescription local hot-wet compress therapy has a significant therapeutic effect on treatment of mastalgia and can significantly improve the breast pain symptom of patients.展开更多
Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one sidedness and inaccuracy of previous studies,which took concentrati...Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one sidedness and inaccuracy of previous studies,which took concentration gradient as mass transfer potential are discussed. The mass transfer process is analyzed from the viewpoint of non equilibrium thermodynamics,by taking generalized thermodynamic driving force as mass transfer potential,and the corresponding mass transfer coefficient is obtained using the heat and mass transfer equilibrium occurring between moist air and water droplets at wet bulb temperature for the sake of avoiding complex tests and providing more accurate formulas. A mathematical model of wet compression is therefore established,and the general laws of wet compression are investigated. The results show that the performance of atomizer is critical for wet compression and wet compression is more suitable for compressors with higher pressure ratio and longer compression time.展开更多
The water absorption and desorption processes of different types of lightweight aggregates were studied.Subsequently,the influences of pre-wetting lightweight aggregates on compressive strength,microhardness,phase com...The water absorption and desorption processes of different types of lightweight aggregates were studied.Subsequently,the influences of pre-wetting lightweight aggregates on compressive strength,microhardness,phase composition,hydration parameters and micromorphology of the cement pastes were investigated.The results showed that the water absorption and desorption capacities of the lightweight aggregates increased with the decrease of the densification degree.With the addition of pre-wetting lightweight aggregates,the compressive strength of the cement pastes would increase.Moreover,the enhancement effect was more obviously with the desorption capacity of pre-wetting lightweight aggregates increasing.Especially,sample S1 with pre-wetting red-mud ceramisites had the highest compressive strength,of which increased to 49.4 MPa after 28 d curing age.The reason is that mainly because the addition of pre-wetting lightweight aggregates can promote the generation of C–S–H gels in the interfacial zone,and the hydration degree of the interfacial zone increases with the water desorption of pre-wetting lightweight aggregates increasing.It is contributed to optimize the microstructure to enhance microhardness of the interfacial zone,resulting in the compressive strength of the cement-based materials improving.Therefore,the pre-wetting lightweight aggregates with high porosity and strength are the potential internal curing agents for high-strength lightweight concretes.展开更多
The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lower...The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wetmilling（reducing d50 to as low as 2.02 μm） in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early-and late-stage strengths, are significantly mitigated. When d（50）=2.02 μm, the slurry becomes strongly alkaline（pH=12.16） compared to the initial d（50）=20.75 μm（pH=9.49）, and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.50776021
文摘In order to study the effects of wet compression on a transonic compressor,a full 3-D steady numerical simulation was carried out under varying conditions.Different injected water flow rates and droplet diameters were considered.The effect of wet compression on the shock,separated flow,pressure ratio,and efficiency was investigated.Additionally,the effect of wet compression on the tip clearance when the compressor runs in the near-stall and stall situations was emphasized.Analysis of the results shows that the range of stable operation is extended,and that the pressure ratio and inlet air flow rate are also increased at the near-stall point.In addition,it seems that there is an optimum size of the droplet diameter.
基金Supported by Basic Scientific Research Project of Beijing University of Chinese Medicine(2015-JYB-XS166)Project of National Natural Science Foundation(3157397)+2 种基金Project of Beijing Natural Science Foundation(7162082)Beijing TCM Science and Technology Development Fund Project(JJ2015-13)Beijing Municipal Health System High-level Health Technology Talents Training Program(2015-3-113)
文摘[Objectives] To observe the clinical therapeutic efficacy of local hot-wet compress therapy of digestion ointment prescription on the patients with moderate and severe mastalgia. [Methods] Firstly,60 patients with mastalgia were selected,and divided into the experimental group and control group( 30 cases for each group). The control group was treated with acupuncture at distal point,and the experimental group was treated with TCM local hot-wet compress therapy combined with acupuncture at distal point. Then,the clinical therapeutic efficacy of two groups was compared. [Results]The experimental group was superior to the control group in relieving the breast pain,improving emotional integral,reducing breast lumps,improving lump texture,and improving TCM syndrome integral( P < 0. 05). [Conclusions]The digestion ointment prescription local hot-wet compress therapy has a significant therapeutic effect on treatment of mastalgia and can significantly improve the breast pain symptom of patients.
文摘Wet compression is an effective way to enhance the performance of gas turbines and it has attracted a good deal of attention in recent years. The one sidedness and inaccuracy of previous studies,which took concentration gradient as mass transfer potential are discussed. The mass transfer process is analyzed from the viewpoint of non equilibrium thermodynamics,by taking generalized thermodynamic driving force as mass transfer potential,and the corresponding mass transfer coefficient is obtained using the heat and mass transfer equilibrium occurring between moist air and water droplets at wet bulb temperature for the sake of avoiding complex tests and providing more accurate formulas. A mathematical model of wet compression is therefore established,and the general laws of wet compression are investigated. The results show that the performance of atomizer is critical for wet compression and wet compression is more suitable for compressors with higher pressure ratio and longer compression time.
基金Funded by National Natural Science Foundation of China(Nos.51878003 and 51778513)Major Special Science and Technology Project of Hubei Province(No.2018AAA001)the National Basic Research Program of China(973 Program)(No.2015CB655101).
文摘The water absorption and desorption processes of different types of lightweight aggregates were studied.Subsequently,the influences of pre-wetting lightweight aggregates on compressive strength,microhardness,phase composition,hydration parameters and micromorphology of the cement pastes were investigated.The results showed that the water absorption and desorption capacities of the lightweight aggregates increased with the decrease of the densification degree.With the addition of pre-wetting lightweight aggregates,the compressive strength of the cement pastes would increase.Moreover,the enhancement effect was more obviously with the desorption capacity of pre-wetting lightweight aggregates increasing.Especially,sample S1 with pre-wetting red-mud ceramisites had the highest compressive strength,of which increased to 49.4 MPa after 28 d curing age.The reason is that mainly because the addition of pre-wetting lightweight aggregates can promote the generation of C–S–H gels in the interfacial zone,and the hydration degree of the interfacial zone increases with the water desorption of pre-wetting lightweight aggregates increasing.It is contributed to optimize the microstructure to enhance microhardness of the interfacial zone,resulting in the compressive strength of the cement-based materials improving.Therefore,the pre-wetting lightweight aggregates with high porosity and strength are the potential internal curing agents for high-strength lightweight concretes.
基金Funded by National Natural Science Foundation of China(No.51372076)the Technology Innovation Major Project of Hubei Province(No.2017ACA178)the Science and Technology Support Program of Hubei Province(No.2015BCA244)
文摘The phosphorus slag（PS） can be used as a supplementary cementitious material due to its potential hydrating activity. However, its usage has been limited by its adverse effects, including prolonged setting and lowered early-stage strength. In this study, we achieved ultrafine granulation of PS using wetmilling（reducing d50 to as low as 2.02 μm） in order to increase its activity, and examined the physico-chemical properties of the resulting materials, including particle-size distribution, slurry pH, zeta potential, and activity index, as well as how their replacement level and granularity affect the setting time and mechanical performance of PS-cement mixture systems. The results suggested that as the granularity increases, there are significant boosts in the uniformity of particle sizes, slurry pH, and activity index, and the effects on cement paste, including setting times, and early-and late-stage strengths, are significantly mitigated. When d（50）=2.02 μm, the slurry becomes strongly alkaline（pH=12.16） compared to the initial d（50）=20.75 μm（pH=9.49）, and the activity is increased by 73%; when used at 40% replacement, the PS-cement mixture system can reach a 28 d compressive strength of 93.2 MPa, 36% higher than that of the pure cement control group.
