The dynamic response of vitreous carbon to uniaxial strain loading has been investigated by means of the plate impact experiments. The two x cut shorted quartz gauges assembled with impactor and target were used ...The dynamic response of vitreous carbon to uniaxial strain loading has been investigated by means of the plate impact experiments. The two x cut shorted quartz gauges assembled with impactor and target were used to obtain the wave speeds in material and the stress histories at the sample gauge interface. The wave speed and stress histories were analyzed to determine the peak state in the sample. For compressive stress up to 4 0 GPa, the wave profiles were observed to be simple and steady, the uniaxial strain response is essentially nonlinear elastic, and no inelastic deformation has been found. All the experiment results indicate that the Hugoniot curve of vitreous carbon is concave downward just like that of fused silicon. There is no shock wave but the compressed wave propagating in the impacted samples.展开更多
Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2...Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2 diabetic patient presenting anterior segment and vitreous hemorrhages that resolved three days after treatment with a single intravitreal injection of dobesilate.展开更多
Large-scale and long-time molecular-dynamics simulations are used to investigate the temperature dependences of elastic properties for amorphous SiO2. The elastic moduli increase in a temperature range up to 1600 K an...Large-scale and long-time molecular-dynamics simulations are used to investigate the temperature dependences of elastic properties for amorphous SiO2. The elastic moduli increase in a temperature range up to 1600 K and decrease thereafter. The anomalous behaviour in elasticity is explained by analysing the changes of atomic-scale structure with respect to increment of temperature. The mechanism originates predominantly from distortion of the SiO4 tetrahedra network in low-temperature ranges. At an elevated temperature range, thermal-induced Si-O bond stretching dominates the process and leads to normal temperature dependence of elastic properties.展开更多
Our previous experiments demonstrated the occurrence of retinal lipidperioxidation following vitreous hemorrhage.In the present study,0.2ml ofautologous whole blood was injected into the vitreous of both eyes in rabbi...Our previous experiments demonstrated the occurrence of retinal lipidperioxidation following vitreous hemorrhage.In the present study,0.2ml ofautologous whole blood was injected into the vitreous of both eyes in rabbits.One eye of each rabbit received an additional injection of 0.2ml of superoxidedismutase (SOD,794 U);the other eye served as a control.The malondialdehyde(MDA) in the retina was assayed with fluorescence spectrophotometry.The resultsshowed that the MDA was significantly lower in eyes injected with SOD (0.047±0.010 nmol/mg) than in control eyes (0.096±0.011 nmol/mg,P【0.05) 10d afterinjection.Ultrastructural examination revealed that the photoreceptor cells of theeyes with SOD injection were relatively normal.It is suggested that SOD can pro-tect the retina from lipid peroxidation.展开更多
The effect of mineralogy and texture on the beneficiation of goethitic ores from two different origins is highlighted. Sample A having 54.47% Fe with 8.57% loss of ignition （LOl） indicates the presence of vitreous a...The effect of mineralogy and texture on the beneficiation of goethitic ores from two different origins is highlighted. Sample A having 54.47% Fe with 8.57% loss of ignition （LOl） indicates the presence of vitreous and ochreous goethite, martite and microplaty hematite as the major minerals. Sample B contains 56.90% Fe with 14.4% LOI. There is a pisolithic laterite containing vitreous and ochreous goethite, quartz, kaolinitic clay and there is no hematite mineral. The liberated minerals in -150 ＋ 100 μm size class are 74% for Sample A and 37% only for Sample B which shows that the Sample A appears to be more amenable to beneficiate. A concentrate of 46.7% with 63.22% Fe could be recovered from Sample A while subjected to gravity separation followed by wet magnetic separation. The Sample B does not respond to gravity and magnetic separation due to its complex mineralogy. However, calcination of the Sample B followed by magnetic separation gives the encouraging results. Thus, anomalous behaviour of the goethite dominated ores in beneficiation is attributed to the different textural and liberation characteristic.展开更多
文摘The dynamic response of vitreous carbon to uniaxial strain loading has been investigated by means of the plate impact experiments. The two x cut shorted quartz gauges assembled with impactor and target were used to obtain the wave speeds in material and the stress histories at the sample gauge interface. The wave speed and stress histories were analyzed to determine the peak state in the sample. For compressive stress up to 4 0 GPa, the wave profiles were observed to be simple and steady, the uniaxial strain response is essentially nonlinear elastic, and no inelastic deformation has been found. All the experiment results indicate that the Hugoniot curve of vitreous carbon is concave downward just like that of fused silicon. There is no shock wave but the compressed wave propagating in the impacted samples.
文摘Vitreous hemorrhages are important clinical manifestations of proliferative diabetic retinopathy. Non-cleared vitreous hemorrhages could lead to hemosiderosis bulbi and glaucoma. Here, we describe the case of a type 2 diabetic patient presenting anterior segment and vitreous hemorrhages that resolved three days after treatment with a single intravitreal injection of dobesilate.
基金Supported by the National Natural Science Foundation of China and the National Science Fund for Distinguished Young Scholars under Grant Nos 90403027 and 50772114.
文摘Large-scale and long-time molecular-dynamics simulations are used to investigate the temperature dependences of elastic properties for amorphous SiO2. The elastic moduli increase in a temperature range up to 1600 K and decrease thereafter. The anomalous behaviour in elasticity is explained by analysing the changes of atomic-scale structure with respect to increment of temperature. The mechanism originates predominantly from distortion of the SiO4 tetrahedra network in low-temperature ranges. At an elevated temperature range, thermal-induced Si-O bond stretching dominates the process and leads to normal temperature dependence of elastic properties.
基金Supported by the National Natural Science Foundation of China(No.3870822)
文摘Our previous experiments demonstrated the occurrence of retinal lipidperioxidation following vitreous hemorrhage.In the present study,0.2ml ofautologous whole blood was injected into the vitreous of both eyes in rabbits.One eye of each rabbit received an additional injection of 0.2ml of superoxidedismutase (SOD,794 U);the other eye served as a control.The malondialdehyde(MDA) in the retina was assayed with fluorescence spectrophotometry.The resultsshowed that the MDA was significantly lower in eyes injected with SOD (0.047±0.010 nmol/mg) than in control eyes (0.096±0.011 nmol/mg,P【0.05) 10d afterinjection.Ultrastructural examination revealed that the photoreceptor cells of theeyes with SOD injection were relatively normal.It is suggested that SOD can pro-tect the retina from lipid peroxidation.
基金Ministry of Steel for funding the research work (GAP 0224)
文摘The effect of mineralogy and texture on the beneficiation of goethitic ores from two different origins is highlighted. Sample A having 54.47% Fe with 8.57% loss of ignition （LOl） indicates the presence of vitreous and ochreous goethite, martite and microplaty hematite as the major minerals. Sample B contains 56.90% Fe with 14.4% LOI. There is a pisolithic laterite containing vitreous and ochreous goethite, quartz, kaolinitic clay and there is no hematite mineral. The liberated minerals in -150 ＋ 100 μm size class are 74% for Sample A and 37% only for Sample B which shows that the Sample A appears to be more amenable to beneficiate. A concentrate of 46.7% with 63.22% Fe could be recovered from Sample A while subjected to gravity separation followed by wet magnetic separation. The Sample B does not respond to gravity and magnetic separation due to its complex mineralogy. However, calcination of the Sample B followed by magnetic separation gives the encouraging results. Thus, anomalous behaviour of the goethite dominated ores in beneficiation is attributed to the different textural and liberation characteristic.
