Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlation...Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlations between PCI intensity and park characteristics such as park area,landscape shape index(LSI),green ratio and altitude were analyzed,using 3 010 temperature and humidity data from measurements in six parks with typical park characteristics in Chongqing,China.The results indicate that:1) the main factor determining PCI intensity is park area,which leads to obvious cool island effect when it exceeds 14 hm2;2) there is a negative correlation between PCI intensity and LSI,showing that the rounder the park shape is,the better the cool island effect could be achieved;3) regression analysis of humidity and PCI intensity proves that photosynthesis midday depression(PMD) is an important factor causing the low PCI intensity at 13:00;4) the multivariable linear regression model proposed here could effectively well predict the daily PCI intensity in mountain cities.展开更多
Variations of wind effects on large cooling towers observed at different turbulence intensities for our previous full-scale measurements might be caused by the inherent uncertainties in our physical experiments.Accord...Variations of wind effects on large cooling towers observed at different turbulence intensities for our previous full-scale measurements might be caused by the inherent uncertainties in our physical experiments.Accordingly,the one-way analysis of variance(ANOVA)technique is employed for analyzing the data measured on the prototype Pengcheng cooling tower.Because ANOVA indicates that the variations of full-scale wind effects are basically the effects of turbulence intensity,the empirical results of wind loads on cooling towers obtained by generalizing physical experimental data without considering the turbulence intensity effects are updated using model test results obtained in multiple flow fields.The empirical fluctuating wind pressure distribution is updated based on the fact that the fluctuating wind pressure coefficient linearly increases with the increase in the turbulence intensity,and the empirical formulae of the spectra and the coherences is updated based on conservative assumptions.Comparisons of the empirical results and full-scale measurement data suggest that the original empirical results are either too conservative or unsafe for use.However,economic efficiency and conservativeness will be balanced if the updated empirical results are employed for the wind engineering design.展开更多
This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer (CASA), as well as assess the effects of cryopreservation on the sperm ...This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer (CASA), as well as assess the effects of cryopreservation on the sperm subpopulation structure and evaluate bull variability. The semen of eight Bulgarian Murrah bulls was collected by four times in an interval of one week each. The semen was cryopreserved following a standard protocol and sperm kinematics was assessed. Clustering methods were applied to individual sperms, forming two significantly different (P 〈 0.05) subpopulations (P1 and P2). Subpopulation P1 represents those spermatozoa that moved most rapidly and progressively (46.29%), and subpopulation P2 includes spermatozoa with relatively low velocity or poorly motile but with high progressiveness (53.41%). There was a decline on the population of P1 sperms from fresh (52.52%), pre-freeze (45.73%) to post-thaw (35.17%) stages and significant difference on the sperm kinematics between P1 and P2. A significant decline in the values of distance, velocity and amplitude of lateral head (ALH) parameters were observed at post-thaw stage, while an increase was observed on trajectory and beat cross frequency (BCF) kinematics. Values of sperm kinematics were also significantly different (P 〈 0.05) among all bulls. The frequency distribution of spermatozoa on both subpopulations P1 and P2 was quite similar for all bulls in pre-freeze and post-thaw stages, but with significant (P 〈 0.05) variability on fresh stage. Bulls with the highest maintained frequency of P1 sperms are denoted as good freezer bulls. In sum, kinematic characterization of water buffalo sperm and clustering into subpopulation enable to identify bulls that are more resistant to cryopreservation and production of quality semen for genetic propagation.展开更多
The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is n...The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is not the case in reality, and a low efficient air conditioning system results from this assumption. A simulation and analysis of the cooling load distribution of an office building in Hong Kong with TRANSYS software is provided in this paper. A typical office is divided into 13 zones for simulation, including external zone, medial zone and internal zone in the north, the south, the east and the west respectively and a central zone, instead of 4 directional zone. The result shows there is much cooling load difference between each zone, and more attention should be paid to uneven indoor cooling and heating load distribution to further guide the design.展开更多
It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction be...It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction between urban parks and their urban surroundings, this paper takes the Temple of Heaven Park (THP) as an example of a park station and focuses on analyzing the differences with a nearby urban station.THP is located in the center of Beijing, and the nearest urban station is Tian An Men. It is interesting that the cooling effect of THP reaches a peak and remains stable when its city background urban heat island (UHI) varies within a given range, but becomes unstable when the UHI goes beyond the range. This is called an enhanced cooling effect in this paper. As a result, the UHi intensities (UHIIs) are calculated in order to comprehend the role of the park cooling effect in the urban heating characteristics of Beijing. By comparison with five other park-district pairs, this paper attempts to identify the causes of the enhanced cooling effect. It is found that six park-district pairs consistently demonstrate a persistently stronger cooling rate during the night, and that the water coverage might be a key factor in enhancing the park cooling effect. Based on further investigation of the influence of surrounding UHIs on the park cooling effect, it is found that the UHII differences in park-district pairs show quasi-linear changes within a given range as the UHli of the surrounding district increases.展开更多
The wastewater discharged from the 1.0 Mt/a ethylene unit at Maoming Petrochemical Company was separated according to its quality, and a major part ofwastewater with better quality was properly treated via the process...The wastewater discharged from the 1.0 Mt/a ethylene unit at Maoming Petrochemical Company was separated according to its quality, and a major part ofwastewater with better quality was properly treated via the process of"IRABF + high-efficiency fiber filtering + disinfection" to make the wastewater quality comply with the quality of recycled cooling water, so that the technique for reused petrochemical wastewater was more reliable technically and more reasonable economically,展开更多
Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs (multi-level apartment buildings), using field measurements to monitor environmental conditions a...Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs (multi-level apartment buildings), using field measurements to monitor environmental conditions and condenser operation, revealed increases in the inlet air temperature at the condensers at the upper floors, which in turn increased the power and energy requirements for these units and decreased their cooling capacities. Results indicated that a decrease of up to 16,000 tons in cooling capacity and an increase of up to 67.2 MW in the national peak load demand might be reached for a 4 ℃ temperature differential for Kuwait conditions. It is recommended that the condensers be placed in the wind pathway to minimize the impact of heat rejection and stack effect and to optimize the operation of split-type air-conditioning units, and that other factors regarding installation setup and location are investigated.展开更多
Refrigerant is a medium used in refrigeration cycle. Until now in thermodynamic models calculations of refrigerant is not considered with lubricant and moist air but as an ideal pure gas (without any contaminants). ...Refrigerant is a medium used in refrigeration cycle. Until now in thermodynamic models calculations of refrigerant is not considered with lubricant and moist air but as an ideal pure gas (without any contaminants). This is also the case in refrigeration cycle where the refrigerant is very often considered as an ideal one. Lubricant, air and water vapour are not considered in thermodynamic calculations in spite of their existence. The problems in the existing research are summarized. A further study is suggested on refrigerant systems. This circulation of such calculations is at the origin of a deviation from a theoretical behaviour. This article aims at reviewing the researches of oil-refrigerant, air-refrigerant, moist air-refrigerant or oil-moist air-refrigerant mixtures and focuses particularly on mixture enthalpy calculation. This paper deals with the description of the real mixture of refrigerant and contaminants (lubricant, water, moist air and other remains of refrigerants at elevated pressures and temperatures) which flow in a refrigerating cycle and the main point of this paper is to appoint thermodynamic parameters of such a mixture using the thermodynamic formulas.展开更多
Sixty six water samples were collected from inlets, inside and outlets of cooling towers (22 samples each, once a week). Samples were screened for bacterial colonization with special focus on Legionella. Percentage ...Sixty six water samples were collected from inlets, inside and outlets of cooling towers (22 samples each, once a week). Samples were screened for bacterial colonization with special focus on Legionella. Percentage occurrence of predominant bacteria present in water samples collected from inlets included: Klebsiella (95.45%), Enterobacter (90.9%), Pseudomonas (86.36%), Escherichia coli (81.81%), and Legionella (72.72%). While those predominant in water inside cooling towers were: Pseudomonas (100%), Staphylococci (81.81%), Legionella (81.81%) and Bacillus (72.72%). Incidence of Legionella recovered from inside and outlets of cooling towers sites was similar. Four species of Legionella were identified in water samples collected from inlets, inside and outlets of cooling towers, in the following consecutive frequencies L. pneumophila (72.72%, 81.81% and 81.81%), L. jordans (18.18%, 36.36% and 27.27%), L. dumffii (9.09%, 22.72% and 22.72%) and L. oekidegenes (4.54%, 13.63% and 18.18%). The increased percentage occurrence of Legionella in water collected from inlets and inside cooling towers, as well as those of Pseudomonas and Staphylococci suggest that Legionella is also a hardy organism, being potentially survive as free organism despite water disinfection.展开更多
Continuous conflict has affected the migration of the Palestinians. Following the first exodus in 1948, they continued to migrate out of compulsion or for practical reasons. This paper clarifies the contemporary situa...Continuous conflict has affected the migration of the Palestinians. Following the first exodus in 1948, they continued to migrate out of compulsion or for practical reasons. This paper clarifies the contemporary situation and perceptions of migration among the Palestinians in the West Bank, Gaza Strip, and East Jerusalem. Given the influence of regulations, this study situates those areas as part of the Israeli democratic system. Based on an original poll survey conducted in the summer of 2011, the analysis attempts to explain the relationship between migration and citizenship. People's migration is analyzed in relation to their different statuses as citizens. The variants of the statuses are considered to be a result of the system of stratified citizenship, and it is characterized as a component of the democratic system of Israel.展开更多
The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene (BHT) supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artifici...The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene (BHT) supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artificial vagina. Semen with motility of more than 70% was included in the experiment. Tris-fructose-glycerol-egg yolk extender containing 0, 1, 3 and 7 mM BHT was used to dilute semen to final concentration of 200 × 10^6 cells/ml. Diluted semen was frozen in 0.25 mL straws and frozen semen was thawed in a 37 ℃ water bath for 15 sec before being evaluated at 0 and 1 hour. Sperm motility at 0 and 1 hour after thawing did not differ among groups tested (ranged 47.86-53.57 and 21.79-24.29 respectively). At 0 hour after thawing, percentage of live sperm of 3 mM BHT (37.39% ± 2.91%) was lower than those of 0 and 1 mM BHT (43.71%± 2.76% and 41.46% ±2.59% respectively, P 〈 0.05) but not different from 7 mM BHT (40.89%± 2.50%). The effect was more significant at 1 hour after thawing and 3 mM BHT (32.07% ± 2.45%) suppressed live cells more than other concentrations (ranged 35.07%-37.46%, P 〈 0.05). At 0 hour after thawing, percentage of membrane integrity (hypo-osmotic swelling test) was not affected by BHT concentration (ranged 23.89%-28.54%). However, at 1 hour after thawing, percentage of membrane integrity of 3 mM BHT (19.75% ± 1.41%) was lower that of 7 mM BHT (23.29% ± 1.88%, P 〈 0.05) but not different from those of 0 and 1 mM BHT (20.32% ±1.81% and 22.07% ± 2.27% respectively). No significant effect was found on percentage of abnormal sperm. There was no effect of BHT supplementation in extender on most of the Hamilton-thorn motility analyser parameters. It may be concluded that 3 mM BHT can be harmful to fighting bull spermatozoa and lower concentrmion can be used without detrimental effect. Further study may be needed to verify use of BHT in lower range of concentrations.展开更多
The stratotypic section of the Shanxi Formation in western hills of Taiyuan, Shanxi Province, its bottom boundary drawn at the base of the Beichagou sandstone and top demarcation at the base of the Luotuobozi sandston...The stratotypic section of the Shanxi Formation in western hills of Taiyuan, Shanxi Province, its bottom boundary drawn at the base of the Beichagou sandstone and top demarcation at the base of the Luotuobozi sandstone, is of ma-展开更多
Let E be a Banach space. If {T_m} is a sequence of uniform bounded operators such that {T_nx_n} is compact for any bounded sequence {x_n}, we say that {T_n} is a general collective cempact operator sequence.
基金Project(2006BAJ02A02-05) supported by the National Key Technologies R&D Program of China
文摘Evaluating how park characteristics affect the formation of a park cool island(PCI) is the premise of guiding green parks planning in mountain cities.The diurnal variation of PCI intensity was achieved,and correlations between PCI intensity and park characteristics such as park area,landscape shape index(LSI),green ratio and altitude were analyzed,using 3 010 temperature and humidity data from measurements in six parks with typical park characteristics in Chongqing,China.The results indicate that:1) the main factor determining PCI intensity is park area,which leads to obvious cool island effect when it exceeds 14 hm2;2) there is a negative correlation between PCI intensity and LSI,showing that the rounder the park shape is,the better the cool island effect could be achieved;3) regression analysis of humidity and PCI intensity proves that photosynthesis midday depression(PMD) is an important factor causing the low PCI intensity at 13:00;4) the multivariable linear regression model proposed here could effectively well predict the daily PCI intensity in mountain cities.
基金The National Natural Science Foundation of China(No.51908124),the China Postdoctoral Science Foundation(No.2016M601793).
文摘Variations of wind effects on large cooling towers observed at different turbulence intensities for our previous full-scale measurements might be caused by the inherent uncertainties in our physical experiments.Accordingly,the one-way analysis of variance(ANOVA)technique is employed for analyzing the data measured on the prototype Pengcheng cooling tower.Because ANOVA indicates that the variations of full-scale wind effects are basically the effects of turbulence intensity,the empirical results of wind loads on cooling towers obtained by generalizing physical experimental data without considering the turbulence intensity effects are updated using model test results obtained in multiple flow fields.The empirical fluctuating wind pressure distribution is updated based on the fact that the fluctuating wind pressure coefficient linearly increases with the increase in the turbulence intensity,and the empirical formulae of the spectra and the coherences is updated based on conservative assumptions.Comparisons of the empirical results and full-scale measurement data suggest that the original empirical results are either too conservative or unsafe for use.However,economic efficiency and conservativeness will be balanced if the updated empirical results are employed for the wind engineering design.
文摘This study aimed to identify and characterize the sperm subpopulations existing in water buffalo semen using a computer assisted sperm analyzer (CASA), as well as assess the effects of cryopreservation on the sperm subpopulation structure and evaluate bull variability. The semen of eight Bulgarian Murrah bulls was collected by four times in an interval of one week each. The semen was cryopreserved following a standard protocol and sperm kinematics was assessed. Clustering methods were applied to individual sperms, forming two significantly different (P 〈 0.05) subpopulations (P1 and P2). Subpopulation P1 represents those spermatozoa that moved most rapidly and progressively (46.29%), and subpopulation P2 includes spermatozoa with relatively low velocity or poorly motile but with high progressiveness (53.41%). There was a decline on the population of P1 sperms from fresh (52.52%), pre-freeze (45.73%) to post-thaw (35.17%) stages and significant difference on the sperm kinematics between P1 and P2. A significant decline in the values of distance, velocity and amplitude of lateral head (ALH) parameters were observed at post-thaw stage, while an increase was observed on trajectory and beat cross frequency (BCF) kinematics. Values of sperm kinematics were also significantly different (P 〈 0.05) among all bulls. The frequency distribution of spermatozoa on both subpopulations P1 and P2 was quite similar for all bulls in pre-freeze and post-thaw stages, but with significant (P 〈 0.05) variability on fresh stage. Bulls with the highest maintained frequency of P1 sperms are denoted as good freezer bulls. In sum, kinematic characterization of water buffalo sperm and clustering into subpopulation enable to identify bulls that are more resistant to cryopreservation and production of quality semen for genetic propagation.
文摘The cooling and heating load distribution of large area air-conditioned room such as “open” offices, shopping malls and waiting rooms is usually assumed to be even in air conditioning system design. However, it is not the case in reality, and a low efficient air conditioning system results from this assumption. A simulation and analysis of the cooling load distribution of an office building in Hong Kong with TRANSYS software is provided in this paper. A typical office is divided into 13 zones for simulation, including external zone, medial zone and internal zone in the north, the south, the east and the west respectively and a central zone, instead of 4 directional zone. The result shows there is much cooling load difference between each zone, and more attention should be paid to uneven indoor cooling and heating load distribution to further guide the design.
基金supported by the National Natural Science Foundation of China[grant number 41375069]National Basic Research Program of China[grant number 2012CB957804]Young Talent Programming of China Meteorological Administration
文摘It is claimed that open spaces in cities, such as parks, have an urban cooling effect. However, the relationship between urban parks and adjacent districts is still not explicit. In order to clarify the interaction between urban parks and their urban surroundings, this paper takes the Temple of Heaven Park (THP) as an example of a park station and focuses on analyzing the differences with a nearby urban station.THP is located in the center of Beijing, and the nearest urban station is Tian An Men. It is interesting that the cooling effect of THP reaches a peak and remains stable when its city background urban heat island (UHI) varies within a given range, but becomes unstable when the UHI goes beyond the range. This is called an enhanced cooling effect in this paper. As a result, the UHi intensities (UHIIs) are calculated in order to comprehend the role of the park cooling effect in the urban heating characteristics of Beijing. By comparison with five other park-district pairs, this paper attempts to identify the causes of the enhanced cooling effect. It is found that six park-district pairs consistently demonstrate a persistently stronger cooling rate during the night, and that the water coverage might be a key factor in enhancing the park cooling effect. Based on further investigation of the influence of surrounding UHIs on the park cooling effect, it is found that the UHII differences in park-district pairs show quasi-linear changes within a given range as the UHli of the surrounding district increases.
文摘The wastewater discharged from the 1.0 Mt/a ethylene unit at Maoming Petrochemical Company was separated according to its quality, and a major part ofwastewater with better quality was properly treated via the process of"IRABF + high-efficiency fiber filtering + disinfection" to make the wastewater quality comply with the quality of recycled cooling water, so that the technique for reused petrochemical wastewater was more reliable technically and more reasonable economically,
文摘Analyzing the effects of heat rejection from condensers of split-type air-conditioning units at lower-floors of MLABs (multi-level apartment buildings), using field measurements to monitor environmental conditions and condenser operation, revealed increases in the inlet air temperature at the condensers at the upper floors, which in turn increased the power and energy requirements for these units and decreased their cooling capacities. Results indicated that a decrease of up to 16,000 tons in cooling capacity and an increase of up to 67.2 MW in the national peak load demand might be reached for a 4 ℃ temperature differential for Kuwait conditions. It is recommended that the condensers be placed in the wind pathway to minimize the impact of heat rejection and stack effect and to optimize the operation of split-type air-conditioning units, and that other factors regarding installation setup and location are investigated.
文摘Refrigerant is a medium used in refrigeration cycle. Until now in thermodynamic models calculations of refrigerant is not considered with lubricant and moist air but as an ideal pure gas (without any contaminants). This is also the case in refrigeration cycle where the refrigerant is very often considered as an ideal one. Lubricant, air and water vapour are not considered in thermodynamic calculations in spite of their existence. The problems in the existing research are summarized. A further study is suggested on refrigerant systems. This circulation of such calculations is at the origin of a deviation from a theoretical behaviour. This article aims at reviewing the researches of oil-refrigerant, air-refrigerant, moist air-refrigerant or oil-moist air-refrigerant mixtures and focuses particularly on mixture enthalpy calculation. This paper deals with the description of the real mixture of refrigerant and contaminants (lubricant, water, moist air and other remains of refrigerants at elevated pressures and temperatures) which flow in a refrigerating cycle and the main point of this paper is to appoint thermodynamic parameters of such a mixture using the thermodynamic formulas.
文摘Sixty six water samples were collected from inlets, inside and outlets of cooling towers (22 samples each, once a week). Samples were screened for bacterial colonization with special focus on Legionella. Percentage occurrence of predominant bacteria present in water samples collected from inlets included: Klebsiella (95.45%), Enterobacter (90.9%), Pseudomonas (86.36%), Escherichia coli (81.81%), and Legionella (72.72%). While those predominant in water inside cooling towers were: Pseudomonas (100%), Staphylococci (81.81%), Legionella (81.81%) and Bacillus (72.72%). Incidence of Legionella recovered from inside and outlets of cooling towers sites was similar. Four species of Legionella were identified in water samples collected from inlets, inside and outlets of cooling towers, in the following consecutive frequencies L. pneumophila (72.72%, 81.81% and 81.81%), L. jordans (18.18%, 36.36% and 27.27%), L. dumffii (9.09%, 22.72% and 22.72%) and L. oekidegenes (4.54%, 13.63% and 18.18%). The increased percentage occurrence of Legionella in water collected from inlets and inside cooling towers, as well as those of Pseudomonas and Staphylococci suggest that Legionella is also a hardy organism, being potentially survive as free organism despite water disinfection.
文摘Continuous conflict has affected the migration of the Palestinians. Following the first exodus in 1948, they continued to migrate out of compulsion or for practical reasons. This paper clarifies the contemporary situation and perceptions of migration among the Palestinians in the West Bank, Gaza Strip, and East Jerusalem. Given the influence of regulations, this study situates those areas as part of the Israeli democratic system. Based on an original poll survey conducted in the summer of 2011, the analysis attempts to explain the relationship between migration and citizenship. People's migration is analyzed in relation to their different statuses as citizens. The variants of the statuses are considered to be a result of the system of stratified citizenship, and it is characterized as a component of the democratic system of Israel.
文摘The aim of the present study was to evaluate effect of 3 levels of butylated hydroxytoluene (BHT) supplemented in extender for fighting bull semen. Ejaculates were obtained from 10 healthy fighting bulls by artificial vagina. Semen with motility of more than 70% was included in the experiment. Tris-fructose-glycerol-egg yolk extender containing 0, 1, 3 and 7 mM BHT was used to dilute semen to final concentration of 200 × 10^6 cells/ml. Diluted semen was frozen in 0.25 mL straws and frozen semen was thawed in a 37 ℃ water bath for 15 sec before being evaluated at 0 and 1 hour. Sperm motility at 0 and 1 hour after thawing did not differ among groups tested (ranged 47.86-53.57 and 21.79-24.29 respectively). At 0 hour after thawing, percentage of live sperm of 3 mM BHT (37.39% ± 2.91%) was lower than those of 0 and 1 mM BHT (43.71%± 2.76% and 41.46% ±2.59% respectively, P 〈 0.05) but not different from 7 mM BHT (40.89%± 2.50%). The effect was more significant at 1 hour after thawing and 3 mM BHT (32.07% ± 2.45%) suppressed live cells more than other concentrations (ranged 35.07%-37.46%, P 〈 0.05). At 0 hour after thawing, percentage of membrane integrity (hypo-osmotic swelling test) was not affected by BHT concentration (ranged 23.89%-28.54%). However, at 1 hour after thawing, percentage of membrane integrity of 3 mM BHT (19.75% ± 1.41%) was lower that of 7 mM BHT (23.29% ± 1.88%, P 〈 0.05) but not different from those of 0 and 1 mM BHT (20.32% ±1.81% and 22.07% ± 2.27% respectively). No significant effect was found on percentage of abnormal sperm. There was no effect of BHT supplementation in extender on most of the Hamilton-thorn motility analyser parameters. It may be concluded that 3 mM BHT can be harmful to fighting bull spermatozoa and lower concentrmion can be used without detrimental effect. Further study may be needed to verify use of BHT in lower range of concentrations.
文摘The stratotypic section of the Shanxi Formation in western hills of Taiyuan, Shanxi Province, its bottom boundary drawn at the base of the Beichagou sandstone and top demarcation at the base of the Luotuobozi sandstone, is of ma-
文摘Let E be a Banach space. If {T_m} is a sequence of uniform bounded operators such that {T_nx_n} is compact for any bounded sequence {x_n}, we say that {T_n} is a general collective cempact operator sequence.