Zwick公司生产并获专利的液压复合压缩试验设备（HCCF），用于测试碳素纤维增强塑料（CFRP）和玻璃纤维增强塑料（GFRP）。据该公司称，该装置主要用于测量压缩性能，并适用于标准的测定，如prEN 2850、DIN EN ISO 14126、DIN 65380和OV...Zwick公司生产并获专利的液压复合压缩试验设备（HCCF），用于测试碳素纤维增强塑料（CFRP）和玻璃纤维增强塑料（GFRP）。据该公司称，该装置主要用于测量压缩性能，并适用于标准的测定，如prEN 2850、DIN EN ISO 14126、DIN 65380和OVA—Z10—46—38。开放式C型结构在更换样品时更加方便和快捷，而且其附加的延伸测量系统也使得其操作更为容易。由于其设计和结构的优势，实验样品能够被调整到最佳的位置。从而消除了由传统夹具，如楔型夹具所带来的公差。展开更多
The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of ...The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of 25 on the platform of DEFORM 2D successfully. From the compression experimental results, the flow stress model of this Al alloy is obtained which could be the constitutive equation in the simulation of low-temperature high-speed extrusion process. From the numerical simulation results, there is a higher strain concentration at the entrance of the die and the exit temperature reaches up to 522 ℃ in low-temperature high-speed extrusion, which approaches to the quenching temperature of the 6063 Al alloy. The results show that the low-temperature high-speed extrusion method as a promsing one can reduce energy consumption effectively.展开更多
The mechanical properties of jointed rock masses, such as strength, deformation and the failure mechanism, can be understood only by studying the sensitivity of jointed rock mass strength (both the peak and residual s...The mechanical properties of jointed rock masses, such as strength, deformation and the failure mechanism, can be understood only by studying the sensitivity of jointed rock mass strength (both the peak and residual strengths) to the factors that affect it. An orthogonal design of uniaxial compression tests was simulated on eighteen groups of jointed rock specimens having different geometric and mechanical properties using RFPA2D (Rock Failure Process Analysis) code. The results show that the peak strength is controlled by the geometric parameters of the joints, but that the residual strength is controlled by the mechanical prop- erties of the joint interfaces. The failure mode of jointed rock specimens is mainly shear failure. Joint quantity, or density, is the most important index that affects jointed rock mass strength and engineering quality.展开更多
For Gu-Ag alloy, an important parameter called workability in the forming process of materials can be evaluated by processing maps yielded from the stress-strain data generated by hot compression tests at temperatures...For Gu-Ag alloy, an important parameter called workability in the forming process of materials can be evaluated by processing maps yielded from the stress-strain data generated by hot compression tests at temperatures of 700-850 °C and strain rates of 0.01-10 s-1. And at the true strain of 0.15, 0.35 and 0.55, respectively, the responses of strain-rate sensitivity, power dissipation efficiency and instability parameter to temperature and strain rate were studied. Instability maps and power dissipation maps were superimposed to form processing maps, which reveal the determinate regions where individual metallurgical processes occur and the limiting conditions of flow instability regions. Furthermore, the optimal processing parameters for bulk metal working are identified clearly by the processing maps.展开更多
This work describes a study of tabletting of selected Malaysian herbs such as Eurycoma longifolia Jack, Ficus deltoidea and Morinda citrifolia. These herbs are famous for their therapeutic properties and are used as h...This work describes a study of tabletting of selected Malaysian herbs such as Eurycoma longifolia Jack, Ficus deltoidea and Morinda citrifolia. These herbs are famous for their therapeutic properties and are used as herbal medicine or as medicinal food. A cylindrical uniaxial die of 13 mm was used to compress the herb powders into tablets. Pressures ranging from 7.5 MPa to 75 MPa were applied using a universal testing machine. Two feed weights, 0.5 g and 1.0 g, were used to produce the tablets. A binder, the microcrystalline cellulose known as Avicel, was used to investigate its effect on tabletting. Properties associated with both the binder and the compounds were studied, and binary mixtures with compositions ranging from 10% to 60% were examined. The strength of the herb tablets was then tested using an indirect tensile strength test. Upon compression, the Morinda citrifolia powder showed the highest density compared to that of Avicel. However, due to its high elasticity, the tensile strength of the Morinda citrifolia tablet was the lowest. The experimental data were also verified using an established model for compression property development. The results indicated that this simple approach can be used to understand the tabletting characteristics of these herbs.展开更多
To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elas...To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.展开更多
In order to investigate the compression creep of two kinds of high-performance concrete mixtures used for prestressed members in a bridge,an experimental test under laboratory conditions was carried out.Based on the e...In order to investigate the compression creep of two kinds of high-performance concrete mixtures used for prestressed members in a bridge,an experimental test under laboratory conditions was carried out.Based on the experimental results,a power exponent function was used to model the creep degree of these high-performance concretes(HPCs) for structural numerical analysis,and two series parameters of this function for the HPCs were given with the optimum method of evolution program.The experimental data were compared with CEB-FIP 90 and ACI 92 models.Results show that the two code models both overestimate the creep degree of two HPCs,so it is recommended that the power exponent function should be used for the creep analysis of bridge structure.展开更多
This paper presents a detailed experimental investigation concerning the influence of blade loading (incidence) on the three-dimensional flow in an annular compressor cascade.The data are acquired at four incidence an...This paper presents a detailed experimental investigation concerning the influence of blade loading (incidence) on the three-dimensional flow in an annular compressor cascade.The data are acquired at four incidence angles under low Mach number and low Reynolds number conditions.Experimental techniquss include the oil-film visualization on the profile and the endwall surfaces,the laser-sheet visualization of the flow field inside the blade passage,and the measurement by radial-circumferential traveress using a seven-hole probe.The behavior and nature of the three-dimensional flow with severe separations inside the blade passage and at the exit are obtained.The distributions of the total pressure loss,static pressure,velocity and outflow angle are also given. These results are valuable for establishing the physical model of the three-dimensional complex flow in axial compressors and for examining the computational procedures.展开更多
Objective:To explore the efficacy and mechanism of warm needling moxibustion plus percutaneous kyphoplasty(PKP)for osteoporotic vertebral compression fracture(OVCF)due to kidney deficiency and blood stasis.Methods:A t...Objective:To explore the efficacy and mechanism of warm needling moxibustion plus percutaneous kyphoplasty(PKP)for osteoporotic vertebral compression fracture(OVCF)due to kidney deficiency and blood stasis.Methods:A total of 70 OVCF patients were randomized into a control group and an observation group,with 35 cases in each group.The control group was given PKP treatment,and the observation group was treated with warm needling moxibustion on the basis of the treatment in the control group.The visual analog scale(VAS)and Oswestry disability index(ODI)were scored and the Cobb angle of fractured vertebrae was measured before and after treatment.The re-fracture rate of the adjacent vertebrae was recorded at 1-year follow-up.The serum levels of transforming growth factor(TGF)-β1 and omentin-1 were measured before and after treatment.Results:After treatment,the VAS and ODI scores in both groups decreased(all P<0.05),and all the scores in the observation group were lower than those in the control group(both P<0.05).After treatment,the Cobb angle of fractured vertebrae in both groups decreased(both P<0.05),and the Cobb angle in the observation group was smaller than that in the control group(P<0.05).At 1-year follow-up,the re-fracture rate of the adjacent vertebrae in the observation group was lower than that in the control group(P<0.05).After treatment,the serum levels of TGF-β1 and omentin-1 in both groups increased significantly(all P<0.05),and the serum levels of TGF-β1 and omentin-1 in the observation group were higher than those in the control group(both P<0.05).Conclusion:The treatment of warm needling moxibustion plus PKP can relieve pain,improve dysfunction,promote healing of the injured vertebrae,and reduce the re-fracture rate of the adjacent vertebrae in patients with OVCF due to kidney deficiency and blood stasis,which may be related to the increase of serum TGF-β1 and omentin-1 levels.展开更多
文摘Zwick公司生产并获专利的液压复合压缩试验设备（HCCF），用于测试碳素纤维增强塑料（CFRP）和玻璃纤维增强塑料（GFRP）。据该公司称，该装置主要用于测量压缩性能，并适用于标准的测定，如prEN 2850、DIN EN ISO 14126、DIN 65380和OVA—Z10—46—38。开放式C型结构在更换样品时更加方便和快捷，而且其附加的延伸测量系统也使得其操作更为容易。由于其设计和结构的优势，实验样品能够被调整到最佳的位置。从而消除了由传统夹具，如楔型夹具所带来的公差。
基金Project(2008A09030004) supported by the Major Science and Technology Project of Guangdong Province,ChinaProject(30815009) supported by the Foundation of State Key Laboratory of Advanced Design and Manufacture for Vehicle Body
文摘The hot compression test of 6063 Al alloy was performed on a Gleeble-1500 thermo-simulation machine, and the forming of 6063 rod cxtrudate in low-temperature high-speed extrusion was simulated with extrusion ratio of 25 on the platform of DEFORM 2D successfully. From the compression experimental results, the flow stress model of this Al alloy is obtained which could be the constitutive equation in the simulation of low-temperature high-speed extrusion process. From the numerical simulation results, there is a higher strain concentration at the entrance of the die and the exit temperature reaches up to 522 ℃ in low-temperature high-speed extrusion, which approaches to the quenching temperature of the 6063 Al alloy. The results show that the low-temperature high-speed extrusion method as a promsing one can reduce energy consumption effectively.
基金The financial supports from the National Natural Science Foundation of China (No.50674083)the Eleventh Five-Year Plan of National Scientific and Technological Support of China (No.2008BAB36 B07)the Jiangsu Civil Engineering Graduate Center for Innovation and Academic Communication Foundation
文摘The mechanical properties of jointed rock masses, such as strength, deformation and the failure mechanism, can be understood only by studying the sensitivity of jointed rock mass strength (both the peak and residual strengths) to the factors that affect it. An orthogonal design of uniaxial compression tests was simulated on eighteen groups of jointed rock specimens having different geometric and mechanical properties using RFPA2D (Rock Failure Process Analysis) code. The results show that the peak strength is controlled by the geometric parameters of the joints, but that the residual strength is controlled by the mechanical prop- erties of the joint interfaces. The failure mode of jointed rock specimens is mainly shear failure. Joint quantity, or density, is the most important index that affects jointed rock mass strength and engineering quality.
基金Project(CSTC2009BA4065) supported by the Chongqing Natural Science Foundation,China
文摘For Gu-Ag alloy, an important parameter called workability in the forming process of materials can be evaluated by processing maps yielded from the stress-strain data generated by hot compression tests at temperatures of 700-850 °C and strain rates of 0.01-10 s-1. And at the true strain of 0.15, 0.35 and 0.55, respectively, the responses of strain-rate sensitivity, power dissipation efficiency and instability parameter to temperature and strain rate were studied. Instability maps and power dissipation maps were superimposed to form processing maps, which reveal the determinate regions where individual metallurgical processes occur and the limiting conditions of flow instability regions. Furthermore, the optimal processing parameters for bulk metal working are identified clearly by the processing maps.
文摘This work describes a study of tabletting of selected Malaysian herbs such as Eurycoma longifolia Jack, Ficus deltoidea and Morinda citrifolia. These herbs are famous for their therapeutic properties and are used as herbal medicine or as medicinal food. A cylindrical uniaxial die of 13 mm was used to compress the herb powders into tablets. Pressures ranging from 7.5 MPa to 75 MPa were applied using a universal testing machine. Two feed weights, 0.5 g and 1.0 g, were used to produce the tablets. A binder, the microcrystalline cellulose known as Avicel, was used to investigate its effect on tabletting. Properties associated with both the binder and the compounds were studied, and binary mixtures with compositions ranging from 10% to 60% were examined. The strength of the herb tablets was then tested using an indirect tensile strength test. Upon compression, the Morinda citrifolia powder showed the highest density compared to that of Avicel. However, due to its high elasticity, the tensile strength of the Morinda citrifolia tablet was the lowest. The experimental data were also verified using an established model for compression property development. The results indicated that this simple approach can be used to understand the tabletting characteristics of these herbs.
基金Project(LY13E080021) supported by the Natural Science Foundation of Zhejiang Province,ChinaProject(2011A610072) supported by the Ningbo Municipal Natural Science Foundation,ChinaProject(XKL14D2063) supported by Subject Program of Ningbo University,China
文摘To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation,and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the420 th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.
文摘In order to investigate the compression creep of two kinds of high-performance concrete mixtures used for prestressed members in a bridge,an experimental test under laboratory conditions was carried out.Based on the experimental results,a power exponent function was used to model the creep degree of these high-performance concretes(HPCs) for structural numerical analysis,and two series parameters of this function for the HPCs were given with the optimum method of evolution program.The experimental data were compared with CEB-FIP 90 and ACI 92 models.Results show that the two code models both overestimate the creep degree of two HPCs,so it is recommended that the power exponent function should be used for the creep analysis of bridge structure.
文摘This paper presents a detailed experimental investigation concerning the influence of blade loading (incidence) on the three-dimensional flow in an annular compressor cascade.The data are acquired at four incidence angles under low Mach number and low Reynolds number conditions.Experimental techniquss include the oil-film visualization on the profile and the endwall surfaces,the laser-sheet visualization of the flow field inside the blade passage,and the measurement by radial-circumferential traveress using a seven-hole probe.The behavior and nature of the three-dimensional flow with severe separations inside the blade passage and at the exit are obtained.The distributions of the total pressure loss,static pressure,velocity and outflow angle are also given. These results are valuable for establishing the physical model of the three-dimensional complex flow in axial compressors and for examining the computational procedures.
文摘Objective:To explore the efficacy and mechanism of warm needling moxibustion plus percutaneous kyphoplasty(PKP)for osteoporotic vertebral compression fracture(OVCF)due to kidney deficiency and blood stasis.Methods:A total of 70 OVCF patients were randomized into a control group and an observation group,with 35 cases in each group.The control group was given PKP treatment,and the observation group was treated with warm needling moxibustion on the basis of the treatment in the control group.The visual analog scale(VAS)and Oswestry disability index(ODI)were scored and the Cobb angle of fractured vertebrae was measured before and after treatment.The re-fracture rate of the adjacent vertebrae was recorded at 1-year follow-up.The serum levels of transforming growth factor(TGF)-β1 and omentin-1 were measured before and after treatment.Results:After treatment,the VAS and ODI scores in both groups decreased(all P<0.05),and all the scores in the observation group were lower than those in the control group(both P<0.05).After treatment,the Cobb angle of fractured vertebrae in both groups decreased(both P<0.05),and the Cobb angle in the observation group was smaller than that in the control group(P<0.05).At 1-year follow-up,the re-fracture rate of the adjacent vertebrae in the observation group was lower than that in the control group(P<0.05).After treatment,the serum levels of TGF-β1 and omentin-1 in both groups increased significantly(all P<0.05),and the serum levels of TGF-β1 and omentin-1 in the observation group were higher than those in the control group(both P<0.05).Conclusion:The treatment of warm needling moxibustion plus PKP can relieve pain,improve dysfunction,promote healing of the injured vertebrae,and reduce the re-fracture rate of the adjacent vertebrae in patients with OVCF due to kidney deficiency and blood stasis,which may be related to the increase of serum TGF-β1 and omentin-1 levels.
