The pollen of two tomato varieties, Ryau961721 and Ryau9327D, was adopted in our research. The two tomato varieties were bred by College of Land- scape and Horticulture, Yunnan Agricultural University. The collected p...The pollen of two tomato varieties, Ryau961721 and Ryau9327D, was adopted in our research. The two tomato varieties were bred by College of Land- scape and Horticulture, Yunnan Agricultural University. The collected pollen was stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circumstances. Then it was inoculated to the medium and cultured at 28 ℃ in thermostat incubator. The pollen viability was determined by electron microscope. The results showed that compared to that of pollen stored in control （25 ℃） circumstance, the viability of pollen stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circum- stances for 1 -3 d did not change significantly. In addition, pollen viability trended to decrease with the increase of freeze-thaw cycle and storage time. The pollen lost basically the viability by the 7th d in the storage.展开更多
Temperature was one of the key factors for the living environment of aquatic organisms, especially for shellfish. The effects of temperature was studied on the survival rate and the median lethal time （LT50） of the ...Temperature was one of the key factors for the living environment of aquatic organisms, especially for shellfish. The effects of temperature was studied on the survival rate and the median lethal time （LT50） of the rock scallop Crassadoma gigantea, and the effects of temperature stress on the antioxidant enzymes of rock scallop Crassadoma gigantea were studied in order to explore the effects of temperature on keeping-alive without water and antioxidant system of the rock scallop Crassadoma gigantea. The rock scallop Crassadoma gigantea （shell length （39.7± 5） mm） at different temperatures （5℃ and 15℃）, humidity （moisture treatment, not moisturizing treatment） and oxygen （aerobic treatment, not aerobic treatment） in laboratory was studied by the survival analysis and the analysis of factors affecting the effects of the median lethal time （LTso） in order to investigate the effects of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea. Results showed that low temperature, moisture and aerobic treatment can significantly improve the survival rate and the median lethal time of the rock scallop Crassadoma gigantea （P〈0.05）. The effect of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea was most significant, followed by the effect of oxygen, and that of humidity was the most weakest. Interaction between temperature and humidity, temperature and oxygen significant interaction（P〉0.05）, and interaction between humidity and oxygen interaction was not significant （P〈0.05） in the interaction of three factors. It provided an important basis for the determination of the rock scallop Crassadoma gigantea in the seedling transportation time. In the article, the rock scallop Crassadoma gigantea larvae antioxidant enzymes activity was detected, including SOD activity,CAT activity ,T-A℃ activity （superoxide dismutase activity, catalase activity, total antioxidant capacity） changes through raising the temperature from the low temperature （5℃, 10℃, 15℃, 20℃, 25℃）, to explore the change of the antioxidant enzymes activity under the influence of temperature on the rock scallop Crassadoma gigantea larvae. The SODactivity was significantly lower than that of the other groups （P〈0.05） at 5℃, and the CAT activity had no significant difference between groups （p=0.05）, and the T - AOC level was the lowest significantly below 15℃, 25℃ （P〈0.05）.The SOD and CAT activity had no significant difference in the same experimental time （P〉0.05）, and the T - AOC activity temperature was significantly higher than the rest of the group （P=〈0.05） when temperature at 10℃ and 20℃. The SOD activity had no significant difference （P〉0.05）between groups at 25℃, and the CAT activity was significantly higher than 5℃ 10℃, 15℃ group （P〈0.05）. The T-AOC activity was only lower than 15℃ group （P〉0.05）. It indicated that the high temperature had a clear inducing effect on the CAT activity in the rock scallop Crassadoma gigantea larvae, and had a significant inhibitory effect on the T-AOC activity. The low temperature had a significant inhibitory effect on the activity of T-AOC in the tissue fluid of the scallop. The above results showed that the high and low temperature had a significant effect on the antioxidant enzymes activity of the rock scallop Crassadoma gigantea larvae.展开更多
The uniaxial ratcheting behavior of a polyetherimide (PEI) polymer 'TECAPEI' was studied using stress-controlled cyclic loading at room temperature, including both cyclic tension-compression with non-zero tens...The uniaxial ratcheting behavior of a polyetherimide (PEI) polymer 'TECAPEI' was studied using stress-controlled cyclic loading at room temperature, including both cyclic tension-compression with non-zero tensile mean stress and tension- unloading tests. The experimental observations were focused on the time-dependent ratcheting of the PEI polymer revealed in cyclic tests at diverse stress rates and with different peak stress holding times. The results showed that the PEI polymer shows obvious ratcheting deformation; i.e., the ratcheting strain accumulates progressively in the tensile direction during stress- controlled cyclic tests with non-zero mean stress. The ratcheting is highly dependent on the applied mean stress and stress am-plitude, and is also characterized by a strong time-dependency during the cyclic stressing at diverse stress rates and with different peak stress holding times. The time-dependent ratcheting of the PEI polymer is caused mainly by its remarkable viscosity. A comparison of the ratcheting occurring before and beyond the ultimate stress point of the PEI polymer showed that the ratcheting beyond the ultimate stress point is more significant than that occurring before that point.展开更多
This study explored the potential of using probabilistic neural networks (PNN) to predict shrinkage of thermal insulation mortar.Probabilistic results were obtained from the PNN model with the aid of Parzen non-parame...This study explored the potential of using probabilistic neural networks (PNN) to predict shrinkage of thermal insulation mortar.Probabilistic results were obtained from the PNN model with the aid of Parzen non-parametric estimator of the probability density functions (PDF).Five variables,water-cementitious materials ratio,content of cement,fly ash,aggregate and plasticizer,were employed for input variables,while a category of 56-d shrinkage of mortar was used for the output variable.A total of 192 groups of experimental data from 64 mixtures designed using JMP7.0 software were collected,of which 120 groups of data were used for training the model and the other 72 groups of data for testing.The simulation results showed that the PNN model with an optimal smoothing parameter determined by the curves of the mean square error (MSE) and the number of unrecognized probability densities (UPDs) exhibited a promising capability of predicting shrinkage of mortar.展开更多
基金Supported by College Students’Technology Innovation and Entrepreneurship Action Fund of Yunnan Agricultural University(2014ZKX048)~~
文摘The pollen of two tomato varieties, Ryau961721 and Ryau9327D, was adopted in our research. The two tomato varieties were bred by College of Land- scape and Horticulture, Yunnan Agricultural University. The collected pollen was stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circumstances. Then it was inoculated to the medium and cultured at 28 ℃ in thermostat incubator. The pollen viability was determined by electron microscope. The results showed that compared to that of pollen stored in control （25 ℃） circumstance, the viability of pollen stored in low-temperature （4 ℃） and ultra-low-temperature （-196 ℃） circum- stances for 1 -3 d did not change significantly. In addition, pollen viability trended to decrease with the increase of freeze-thaw cycle and storage time. The pollen lost basically the viability by the 7th d in the storage.
文摘Temperature was one of the key factors for the living environment of aquatic organisms, especially for shellfish. The effects of temperature was studied on the survival rate and the median lethal time （LT50） of the rock scallop Crassadoma gigantea, and the effects of temperature stress on the antioxidant enzymes of rock scallop Crassadoma gigantea were studied in order to explore the effects of temperature on keeping-alive without water and antioxidant system of the rock scallop Crassadoma gigantea. The rock scallop Crassadoma gigantea （shell length （39.7± 5） mm） at different temperatures （5℃ and 15℃）, humidity （moisture treatment, not moisturizing treatment） and oxygen （aerobic treatment, not aerobic treatment） in laboratory was studied by the survival analysis and the analysis of factors affecting the effects of the median lethal time （LTso） in order to investigate the effects of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea. Results showed that low temperature, moisture and aerobic treatment can significantly improve the survival rate and the median lethal time of the rock scallop Crassadoma gigantea （P〈0.05）. The effect of temperature on the survival rate and the median lethal time of the rock scallop Crassadoma gigantea was most significant, followed by the effect of oxygen, and that of humidity was the most weakest. Interaction between temperature and humidity, temperature and oxygen significant interaction（P〉0.05）, and interaction between humidity and oxygen interaction was not significant （P〈0.05） in the interaction of three factors. It provided an important basis for the determination of the rock scallop Crassadoma gigantea in the seedling transportation time. In the article, the rock scallop Crassadoma gigantea larvae antioxidant enzymes activity was detected, including SOD activity,CAT activity ,T-A℃ activity （superoxide dismutase activity, catalase activity, total antioxidant capacity） changes through raising the temperature from the low temperature （5℃, 10℃, 15℃, 20℃, 25℃）, to explore the change of the antioxidant enzymes activity under the influence of temperature on the rock scallop Crassadoma gigantea larvae. The SODactivity was significantly lower than that of the other groups （P〈0.05） at 5℃, and the CAT activity had no significant difference between groups （p=0.05）, and the T - AOC level was the lowest significantly below 15℃, 25℃ （P〈0.05）.The SOD and CAT activity had no significant difference in the same experimental time （P〉0.05）, and the T - AOC activity temperature was significantly higher than the rest of the group （P=〈0.05） when temperature at 10℃ and 20℃. The SOD activity had no significant difference （P〉0.05）between groups at 25℃, and the CAT activity was significantly higher than 5℃ 10℃, 15℃ group （P〈0.05）. The T-AOC activity was only lower than 15℃ group （P〉0.05）. It indicated that the high temperature had a clear inducing effect on the CAT activity in the rock scallop Crassadoma gigantea larvae, and had a significant inhibitory effect on the T-AOC activity. The low temperature had a significant inhibitory effect on the activity of T-AOC in the tissue fluid of the scallop. The above results showed that the high and low temperature had a significant effect on the antioxidant enzymes activity of the rock scallop Crassadoma gigantea larvae.
基金Project (No 2008TPL_Z03) supported by the Key Open Foundation of State Key Laboratory of Traction Power, China
文摘The uniaxial ratcheting behavior of a polyetherimide (PEI) polymer 'TECAPEI' was studied using stress-controlled cyclic loading at room temperature, including both cyclic tension-compression with non-zero tensile mean stress and tension- unloading tests. The experimental observations were focused on the time-dependent ratcheting of the PEI polymer revealed in cyclic tests at diverse stress rates and with different peak stress holding times. The results showed that the PEI polymer shows obvious ratcheting deformation; i.e., the ratcheting strain accumulates progressively in the tensile direction during stress- controlled cyclic tests with non-zero mean stress. The ratcheting is highly dependent on the applied mean stress and stress am-plitude, and is also characterized by a strong time-dependency during the cyclic stressing at diverse stress rates and with different peak stress holding times. The time-dependent ratcheting of the PEI polymer is caused mainly by its remarkable viscosity. A comparison of the ratcheting occurring before and beyond the ultimate stress point of the PEI polymer showed that the ratcheting beyond the ultimate stress point is more significant than that occurring before that point.
基金Project (No. 2006BAJ05B03) supported by the National Key Tech-nologies Supporting Program of China during the 11th Five-Year Plan Period
文摘This study explored the potential of using probabilistic neural networks (PNN) to predict shrinkage of thermal insulation mortar.Probabilistic results were obtained from the PNN model with the aid of Parzen non-parametric estimator of the probability density functions (PDF).Five variables,water-cementitious materials ratio,content of cement,fly ash,aggregate and plasticizer,were employed for input variables,while a category of 56-d shrinkage of mortar was used for the output variable.A total of 192 groups of experimental data from 64 mixtures designed using JMP7.0 software were collected,of which 120 groups of data were used for training the model and the other 72 groups of data for testing.The simulation results showed that the PNN model with an optimal smoothing parameter determined by the curves of the mean square error (MSE) and the number of unrecognized probability densities (UPDs) exhibited a promising capability of predicting shrinkage of mortar.
