[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds i...[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control.展开更多
As a new kind of2D nanomaterials, graphene oxide （GO） with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation （PV） membranes. Such GO membranes were prepared via a...As a new kind of2D nanomaterials, graphene oxide （GO） with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation （PV） membranes. Such GO membranes were prepared via a facile vacuum-assisted method on anodic aluminium oxide disks and applied for the dehydration of butanol. To obtain GO membranes with high performance, effects of pre-treatments, including high-speed centrifugal treat- ment of GO dispersion and thermal treatment of GO membranes, were investigated. In addition, effects of operation conditions on the performance of GO membranes in the PV process and the stability of GO membranes were also studied. It is of benefit to improve the selectivity of GO membrane by pre-treatment that centrifuges the GO dispersion with 10000 r· min^- 1 for 40 min, which could purify the GO dispersion by removing the large size GO sheets. As prepared GO membrane showed high separation performance for the butanol/water system. The separation factor was 230, and the permeability was as high as 3.1 kg·m^- 2·h^-1 when the PV temperature was 50 ℃ and the water content in feed was 10% （by mass）. Meanwhile, the membrane still showed good stability for the dehydration of butanol after running for 1800 min in the PV process. GO membranes are suitable candidates for butanol dehydration via PV process.展开更多
With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, s...With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, scheduling reasonable flow shop production systems can improve productivity and equipment utilization rate, reduce production costs. So the production system of flow shop scheduling problem has become one of the core problems ofmanufactaring enterprises the use of more and more.展开更多
文摘[Objective] This research aimed to study the pre-treatment conditions of head space so as to establish a HS-GC determination method, which is suitable for China's conditions, for trace volatile organic compounds in drinking water. [Method]The preparation method of head space was adopted for the volatile organic compounds in drinking water. [Result] The 20 kinds of volatile organic compounds in drinking water all could be detected simultaneously by using HS-GC-FID method,and they all could be separated well. The HS-GC-FID method could analyze the detected substances qualitatively and quantitatively. In addition, this detection method was characterized by larger linear range of concentration, higher precision, higher detection limit and higher recovery rate. [Conclusion] Under certain conditions, HSGC can reduce the loss of volatile organic compound in drinking water and improve the sensitivity of detection. Moreover, the detection results meet the requirements by quality control.
基金Supported by the National High Technical Research Program of China(2012AA03A606)the Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)+1 种基金the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(12KJA530001)the Innovative Research Team Program by the Ministry of Education of China(IRT13070)
文摘As a new kind of2D nanomaterials, graphene oxide （GO） with 2-4 layers was fabricated rio a modified Hummers method and used for the preparation ofpervaporation （PV） membranes. Such GO membranes were prepared via a facile vacuum-assisted method on anodic aluminium oxide disks and applied for the dehydration of butanol. To obtain GO membranes with high performance, effects of pre-treatments, including high-speed centrifugal treat- ment of GO dispersion and thermal treatment of GO membranes, were investigated. In addition, effects of operation conditions on the performance of GO membranes in the PV process and the stability of GO membranes were also studied. It is of benefit to improve the selectivity of GO membrane by pre-treatment that centrifuges the GO dispersion with 10000 r· min^- 1 for 40 min, which could purify the GO dispersion by removing the large size GO sheets. As prepared GO membrane showed high separation performance for the butanol/water system. The separation factor was 230, and the permeability was as high as 3.1 kg·m^- 2·h^-1 when the PV temperature was 50 ℃ and the water content in feed was 10% （by mass）. Meanwhile, the membrane still showed good stability for the dehydration of butanol after running for 1800 min in the PV process. GO membranes are suitable candidates for butanol dehydration via PV process.
文摘With today＇s global economic downturn and the increasingly fierce market competition, manufacturing enterprises must guarantee the efficient operation of production system, in order to get ahead in the competition, scheduling reasonable flow shop production systems can improve productivity and equipment utilization rate, reduce production costs. So the production system of flow shop scheduling problem has become one of the core problems ofmanufactaring enterprises the use of more and more.
