The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and...The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form classes according to Raunkiaer＇s system. The results show that in total of 68 species at grazed site, hemicryptophytes （He） accounted for 50.00% species, followed by cryptophytes （26.47%）, chamaephytes （16.18%）, phanemphytes （4.41%） and therophytes （2.94%）. At the ungrazed site in 65 plant species, hemicryptophytes （He） accounted fo＇r 49.23% species, cryptophytes （26.15%）, chamaephytes （15.38%）, phanerophytes （6.15%） and ther6phytes （3.08 % species）. In general, hemicrptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form categories were classified as forbs, shrubs, grasses and sedges＇and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites.展开更多
Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositi...Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositions were investigated. Microbial counts were fitted to the modified Gompertz equation and the growth parameters of microorganisms (the initial cell number （N0）, maximum cell number (Nmax), maximum specific growth rate (μmax), lag-phase （（λ）） were obtained as derived parameters. The relationships between growth parameters of microorganisms and the microbial or sensory shelf life were built. The results showed that microbial counts increased and sensory qualities decreased during storage. TPC was predominant bacteria associated with spoilage of sliced onions under tested temperatures and air conditions. High correlation coefficients （r） were found between the lag time （λ） of TPC, coliforms, pseudomonads, yeasts and the microbial or sensory shelf life. The correlations between microbial or sensory shelf life and μmax of five microorganisms were between -0.69 and -0.86. The initial microbial counts （N0） of five microorganisms strains only showed a little correlation, and the maximum microbial counts (Nmax) showed no obvious correlation with shelf life except for LAB and yeasts.展开更多
A Bayesian sequential testing method is proposed to evaluate system reliability index with reliability growth during development.The method develops a reliability growth model of repairable systems for failure censore...A Bayesian sequential testing method is proposed to evaluate system reliability index with reliability growth during development.The method develops a reliability growth model of repairable systems for failure censored test,and figures out the approach to determine the prior distribution of the system failure rate by applying the reliability growth model to incorporate the multistage test data collected from system development.Furthermore,the procedure for the Bayesian sequential testing is derived for the failure rate of the exponential life system,which enables the decision to terminate or continue development test.Finally,a numerical example is given to illustrate the efficiency of the proposed model and procedure.展开更多
Two opposing intellectual traditions and their contem-porary developments regarding the relations among population, available resources, and quality of life as reflected in economic growth are reviewed. What is at iss...Two opposing intellectual traditions and their contem-porary developments regarding the relations among population, available resources, and quality of life as reflected in economic growth are reviewed. What is at issue is whether population growth is detrimental to or beneficial for economic development. Neither of the extreme views gives a complete picture of the interplay among population, resources, and quality of life. Following previous literature on the topic, this paper establishes a more balanced approach that considers the function linking population and quality of life not constant but variable and regards the limitedness of resources as not absolute but relative to regions and societies. The proposed approach is more flexible in better explaining the relation between population and economic growth. China is examined as a case in point to shed light on the interaction of population growth, economic development, and available resources, and its recent post-economic reform experiences showcase the appropriateness of the synthetic approach.展开更多
文摘The present study was conducted in the alpine pastures of Tungnath （30° 14＇ N and 79° 13＇ E） to observe life-form and growth-form patterns of alpine plant species under grazed and ungrazed conditions and to work out the plant life form spectrum. Species were categorized as plant habit, height and length of growth-cycle and life-form classes according to Raunkiaer＇s system. The results show that in total of 68 species at grazed site, hemicryptophytes （He） accounted for 50.00% species, followed by cryptophytes （26.47%）, chamaephytes （16.18%）, phanemphytes （4.41%） and therophytes （2.94%）. At the ungrazed site in 65 plant species, hemicryptophytes （He） accounted fo＇r 49.23% species, cryptophytes （26.15%）, chamaephytes （15.38%）, phanerophytes （6.15%） and ther6phytes （3.08 % species）. In general, hemicrptophyte are dominant^in both sites i.e. graged and ungrazed. Growth form categories were classified as forbs, shrubs, grasses and sedges＇and undershrubs, according to plant habit and height. On the basis of length of the growth cycle, species were categorized as plant species of short growth cycle, intermediate growth cycle and long growth cycle. The short forbs of plant habit and height, had the highest emergence, and grasses and sedges had the lowest emergence in representative species. Percentage of species with long growth cycle was highest in both sites.
基金Item supported by the agricultural keyproject of science and technology commission of Shanghai (No.03319419)
文摘Microbial counts （total aerobic psychrotrophic count （TPC）, lactic acid bacteria （LAB）, coliforms, pseudomonads, yeasts） and sensory properties of sliced onions stored at different temperatures and air compositions were investigated. Microbial counts were fitted to the modified Gompertz equation and the growth parameters of microorganisms (the initial cell number （N0）, maximum cell number (Nmax), maximum specific growth rate (μmax), lag-phase （（λ）） were obtained as derived parameters. The relationships between growth parameters of microorganisms and the microbial or sensory shelf life were built. The results showed that microbial counts increased and sensory qualities decreased during storage. TPC was predominant bacteria associated with spoilage of sliced onions under tested temperatures and air conditions. High correlation coefficients （r） were found between the lag time （λ） of TPC, coliforms, pseudomonads, yeasts and the microbial or sensory shelf life. The correlations between microbial or sensory shelf life and μmax of five microorganisms were between -0.69 and -0.86. The initial microbial counts （N0） of five microorganisms strains only showed a little correlation, and the maximum microbial counts (Nmax) showed no obvious correlation with shelf life except for LAB and yeasts.
基金supported by the National Natural Science Foundation of China (70571083)the Research Fund for the Doctoral Program of Higher Education of China (20094307110013)
文摘A Bayesian sequential testing method is proposed to evaluate system reliability index with reliability growth during development.The method develops a reliability growth model of repairable systems for failure censored test,and figures out the approach to determine the prior distribution of the system failure rate by applying the reliability growth model to incorporate the multistage test data collected from system development.Furthermore,the procedure for the Bayesian sequential testing is derived for the failure rate of the exponential life system,which enables the decision to terminate or continue development test.Finally,a numerical example is given to illustrate the efficiency of the proposed model and procedure.
文摘Two opposing intellectual traditions and their contem-porary developments regarding the relations among population, available resources, and quality of life as reflected in economic growth are reviewed. What is at issue is whether population growth is detrimental to or beneficial for economic development. Neither of the extreme views gives a complete picture of the interplay among population, resources, and quality of life. Following previous literature on the topic, this paper establishes a more balanced approach that considers the function linking population and quality of life not constant but variable and regards the limitedness of resources as not absolute but relative to regions and societies. The proposed approach is more flexible in better explaining the relation between population and economic growth. China is examined as a case in point to shed light on the interaction of population growth, economic development, and available resources, and its recent post-economic reform experiences showcase the appropriateness of the synthetic approach.
