In this paper we propose an absolute error loss EB estimator for parameter of one-side truncation distribution families. Under some conditions we have proved that the convergence rates of its Bayes risk is o, where 0&...In this paper we propose an absolute error loss EB estimator for parameter of one-side truncation distribution families. Under some conditions we have proved that the convergence rates of its Bayes risk is o, where 0<λ,r≤1,Mn≤lnln n (for large n),Mn→∞ as n→∞.展开更多
The aim of this new study is to investigate the ability of using crushed plastic solid wastes in water filtration by using a pilot plant. Two sets of filters were used. The first set represents mono media filters. The...The aim of this new study is to investigate the ability of using crushed plastic solid wastes in water filtration by using a pilot plant. Two sets of filters were used. The first set represents mono media filters. The first filter is a sand media with effective size of 0.65 mm and the others three are plastic media with different grain sizes. The second set represents dual media filters with different depths, the filters were made to operate with the same effective size （0.6-1.0 mm）. These filters were subjected to the same operating conditions of filtration rates and infiuent turbidity. The filters were operated at rates of 5, 7.5, 10, and 12.5 m/h in order to find the optimum filtration velocity with influent turbidity ranged between 7 and l0 NTU （nephelometric turbidity unit）. The results indicated that the single plastic filters and the dual filters produced water of the same high quality as the sand filter. Plastic filters were slower in the development of head losses by about of 8%-78% less and they have longer running time than the sand filter, while the dual filters were slower in the development of head losses by about of 14%-16% and they have longer running time by about of 12%-40% than the sand filter.展开更多
To study the damage mechanism of single-layer reticulated domes subject to severe earthquakes, three limit states of single-layer reticulated domes under earthquakes are defined firstly in this paper. Then, two failur...To study the damage mechanism of single-layer reticulated domes subject to severe earthquakes, three limit states of single-layer reticulated domes under earthquakes are defined firstly in this paper. Then, two failure modes are presented by analyzing damage behaviors, and their characteristics are pointed out respectively. Furthermore, the damage process is analyzed and the causes of structural damage in different levels are studied. Finally, by comparing deformation and vibration status of domes with different failure modes, the principles of different failures are revealed and an integrated frame of damage mechanism is set up.展开更多
In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic Univ...In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic University (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. It has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FINE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANSYS-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.展开更多
文摘In this paper we propose an absolute error loss EB estimator for parameter of one-side truncation distribution families. Under some conditions we have proved that the convergence rates of its Bayes risk is o, where 0<λ,r≤1,Mn≤lnln n (for large n),Mn→∞ as n→∞.
文摘The aim of this new study is to investigate the ability of using crushed plastic solid wastes in water filtration by using a pilot plant. Two sets of filters were used. The first set represents mono media filters. The first filter is a sand media with effective size of 0.65 mm and the others three are plastic media with different grain sizes. The second set represents dual media filters with different depths, the filters were made to operate with the same effective size （0.6-1.0 mm）. These filters were subjected to the same operating conditions of filtration rates and infiuent turbidity. The filters were operated at rates of 5, 7.5, 10, and 12.5 m/h in order to find the optimum filtration velocity with influent turbidity ranged between 7 and l0 NTU （nephelometric turbidity unit）. The results indicated that the single plastic filters and the dual filters produced water of the same high quality as the sand filter. Plastic filters were slower in the development of head losses by about of 8%-78% less and they have longer running time than the sand filter, while the dual filters were slower in the development of head losses by about of 14%-16% and they have longer running time by about of 12%-40% than the sand filter.
基金Sponsored by the National Natural Science Foundation of China(Grant No.90715034)
文摘To study the damage mechanism of single-layer reticulated domes subject to severe earthquakes, three limit states of single-layer reticulated domes under earthquakes are defined firstly in this paper. Then, two failure modes are presented by analyzing damage behaviors, and their characteristics are pointed out respectively. Furthermore, the damage process is analyzed and the causes of structural damage in different levels are studied. Finally, by comparing deformation and vibration status of domes with different failure modes, the principles of different failures are revealed and an integrated frame of damage mechanism is set up.
文摘In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic University (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. It has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FINE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANSYS-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.
