In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(...In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.展开更多
The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers...The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.展开更多
For the problem of price fluctuation in the commodity market, some ordinary differential equation models are proposed and the stability of equilibrium price is studied. In this paper, we develop a mathematic model for...For the problem of price fluctuation in the commodity market, some ordinary differential equation models are proposed and the stability of equilibrium price is studied. In this paper, we develop a mathematic model for price cooperation with diffusion and lag. When the economic parameters satisfy some conditions, the existence and stability of periodic price are investigated.展开更多
Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. ...Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. Methods: The 62 patients with peripheral bronchogenic carcinoma underwent two-phase contrast material-enhanced multislices computed tomography(MSCT) of the chest in a single-breath-hold technique. Two spiral CT scans were obtained at 25 s and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 m L/s by using an autoinjector. Precontrast and postcontrast attenuation on every scan were measured on PACS and CT workstations respectively and peak height was calculated. Enhancement pattern was evaluated on the image obtained at 90 s after injection of contrast medium on PACS and CT workstations respectively. Results: No statistically significant difference in precontrast attenuation, postcontrast attenuation at 25 s and 90 s was found between these measured on a PACS workstation [(40.21 ± 7.03) HU;(55.53 ± 11.09) HU;(75.95 ± 13.45) HU] and those [(39.01 ± 8.95) HU;(56.01 ± 10.91) HU;(76.03 ± 11.95) HU] on a CT workstation(t = 1.140, P = 0.256 > 0.05; t = 1.580, P = 0.149 > 0.05; t = 1.505, P = 0.150﹥0.05). The peak height that calculated on a PACS workstation was 35.74 HU(20 HU). There was not statistically significant difference in peak height between that calculated on a PACS workstation and that on a CT workstation [(37.02 ± 12.05) HU; t = 2.001, P = 0.099 > 0.05]. The tumors showed same enhancement pattern on PACS workstation and CT workstation. Of the 62 cases, 38 showed homogeneous enhancement, 17 showed heterogeneous enhancement, five showed peripheral enhancement, two showed central enhancement, at 90 s. The enhancement pattern revealed on PACS workstation was consistent with feature of peripheral bronchogenic carcinoma. Conclusion: The efficiency and effectiveness of PACS workstation is as same as those of CT workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma.展开更多
基金Supported by the College of Scientific Innovation Significant Cultivation Fund Financing Projects(No.708047)the Key Special Program for Pollution Control(No.2012ZX07101-003)
文摘In this study,the activated sludge model implemented in the BioWin software was validated against full-scale wastewater treatment plant data. Only two stoichiometric parameters(Y p /acetic and the heterotrophic yield(Y H)) required calibration. The value 0.42 was used for Yp /acetic in this study,while the default value of the BioWin software is 0.49,making it comparable with the default values of the corresponding parameter(yield of phosphorus release to substrate uptake(YPO4)) used in ASM2,ASM2 d,and ASM3 P,respectively. Three scenarios were evaluated to improve the performance of the wastewater treatment plant,the possibility of wasting sludge from either the aeration tank or the secondary clarifier,the construction of a new oxidation ditch,and the construction of an equalization tank. The results suggest that construction of a new oxidation ditch or an equalization tank for the wastewater treatment plant is not necessary. However,sludge should be wasted from the aeration tank during wet weather to reduce the solids loading of the clarifiers and avoid effluent violations. Therefore,it is recommended that the design of wastewater treatment plants(WWTPs) should include flexibility to operate the plants in various modes. This is helpful in selection of the appropriate operating mode when necessary,resulting in substantial reductions in operating costs.
基金supported by State Forestry Administration (China) Research and Development Plan(Grant NoSD0639)the Community Comanagement Project of WWF-China
文摘The Crested Ibis(Nipponia Nippon) is endemic to Qinling Mountains of China and was once abundant over vast areas of north-east of Asia habitat.During the 20th century,however,the population declined greatly in numbers.Habitat quality used to be the main threat to this species but recent actions by the government and wildlife protection organizations have brought this under control.With the establishment of Crested Ibis Nature Reserve in China,conflicts between socio-economic development and Crested Ibis conservation have become more acute.How do we deal with the relation between Crested Ibis conservation and community development? In this study,the Crested Ibis Nature Reserve co-management model namely "companies + farmers + Nature Reserve" model is proposed and evaluated with demonstration investigation methods,including continuous six-year fixed-site socio-economic development data of surrounding community,company sales revenue data and monitored data of Crested Ibis Nature Reserve.The results show that farmers' income and conservation awareness increased greatly from 2003 to 2008;company sales revenue has increased by about 20% annually in the recent years;management level has noticeably improved in Nature Reserve,the scope of Crested Ibis habitat has expanded 50 hm2;chemical composition of habitat reduced year after year;and the number of Crested Ibis had been growing annually.At the end,the success of the model is evaluated,and problems in implementation of the model are discussed from the following aspects:management system,co-management concept,economic base of partners,marketing mechanism,technical capacity and so on.
文摘For the problem of price fluctuation in the commodity market, some ordinary differential equation models are proposed and the stability of equilibrium price is studied. In this paper, we develop a mathematic model for price cooperation with diffusion and lag. When the economic parameters satisfy some conditions, the existence and stability of periodic price are investigated.
文摘Objective: The aim of the study was to determine the efficiency and effectiveness of picture archiving and communication system(PACS) workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma. Methods: The 62 patients with peripheral bronchogenic carcinoma underwent two-phase contrast material-enhanced multislices computed tomography(MSCT) of the chest in a single-breath-hold technique. Two spiral CT scans were obtained at 25 s and 90 s respectively after nonionic contrast material was administrated via the antecubital vein at a rate of 4 m L/s by using an autoinjector. Precontrast and postcontrast attenuation on every scan were measured on PACS and CT workstations respectively and peak height was calculated. Enhancement pattern was evaluated on the image obtained at 90 s after injection of contrast medium on PACS and CT workstations respectively. Results: No statistically significant difference in precontrast attenuation, postcontrast attenuation at 25 s and 90 s was found between these measured on a PACS workstation [(40.21 ± 7.03) HU;(55.53 ± 11.09) HU;(75.95 ± 13.45) HU] and those [(39.01 ± 8.95) HU;(56.01 ± 10.91) HU;(76.03 ± 11.95) HU] on a CT workstation(t = 1.140, P = 0.256 > 0.05; t = 1.580, P = 0.149 > 0.05; t = 1.505, P = 0.150﹥0.05). The peak height that calculated on a PACS workstation was 35.74 HU(20 HU). There was not statistically significant difference in peak height between that calculated on a PACS workstation and that on a CT workstation [(37.02 ± 12.05) HU; t = 2.001, P = 0.099 > 0.05]. The tumors showed same enhancement pattern on PACS workstation and CT workstation. Of the 62 cases, 38 showed homogeneous enhancement, 17 showed heterogeneous enhancement, five showed peripheral enhancement, two showed central enhancement, at 90 s. The enhancement pattern revealed on PACS workstation was consistent with feature of peripheral bronchogenic carcinoma. Conclusion: The efficiency and effectiveness of PACS workstation is as same as those of CT workstation in detecting enhancement pattern of peripheral bronchogenic carcinoma.