The subsided water areas with different times of subsidence are chosen to monitor the physicochemical indexes and heavy metal elements. The results indicate that subsided water areas are polluted in different degree. ...The subsided water areas with different times of subsidence are chosen to monitor the physicochemical indexes and heavy metal elements. The results indicate that subsided water areas are polluted in different degree. Some physicochemical indexes of subsided water areas are increased with the development of the subsidence and are changed with the changing of the season. The concentration of As, Cd, Cu, Pb, Se, Zn of subsided water areas is less than national fishery, and surface water quality standards of China , except Hg. And the quality of subsided water hasn't been polluted by heavy metal seriously. Analyzing and appraising the quality of the subsided water can give a reasonable data as basis in using the subsided water resource.展开更多
Through reviewing the generation process and essential characteristics of waterflooding curves, the essence and characteristics of Zhang Jinqing waterflooding curve and Yu Qitai waterflooding curve recommended in Chin...Through reviewing the generation process and essential characteristics of waterflooding curves, the essence and characteristics of Zhang Jinqing waterflooding curve and Yu Qitai waterflooding curve recommended in Chinese Petroleum Industry Standard 'Calculation methods for Recoverable Oil Reserves(SY/T5367—1998)' were discussed, and some technical issues related to the curves were examined in-depth. We found that:(1) All the waterflooding curves are based on empirical formulas derived from oilfield production experience and statistics methods, and can characterize oil displacement features by water quite well.(2) A new waterflooding curve can be derived by combining waterflooding parameters and using different mathematical calculations as long as the parameter combinations and mathematical operation meet a linear relationship, so proposing new waterflooding curves by changing the combination mode has no practical significance anymore.(3) The upwarp of waterflooding curve in the extremely high water cut stage is because the mobility ratio curve has an inflection point with the rapid rise of water cut after reaching a certain value, and the later rapid rise of mobility ratio changes the original two-phase flow dynamics.(4) After entering into water cut stage, all the waterflooding curves with linear relationship can be used to make prediction, even curves with inflection points, as long as they have a straight section above the inflection point.(5) Actual data of waterflooding oilfields has proved that Type A, Zhang Jinqing and Yu Qitai waterflooding curves all can predict accurately oil recoverable reserves in extremely high water cut stage and can be promoted.展开更多
目的了解2022年省、市、县疾控机构(Center for Disease Control and Prevention,CDC)对《生活饮用水卫生标准》(GB 5749-2006)中规定的106项指标的检测能力,分析省、市、县各指标检测能力不足的主要原因。方法收集2022年度全国各级CDC...目的了解2022年省、市、县疾控机构(Center for Disease Control and Prevention,CDC)对《生活饮用水卫生标准》(GB 5749-2006)中规定的106项指标的检测能力,分析省、市、县各指标检测能力不足的主要原因。方法收集2022年度全国各级CDC水质检测能力数据,对省级、地市级CDC的42项常规指标、64项非常规指标和对县级CDC的42项常规指标不具备检测能力的机构占比及不能检测的原因占比进行分析。结果省级CDC检测能力不足主要体现在总α放射性、总β放射性(4个省级,占比14%)和贾第鞭毛虫、隐孢子虫(6个省级,21%),主要原因均为设备配置不到位(100%),其次是无检测人员(50%~75%)。地市级CDC常规指标检测能力不足主要体现在总α放射性和总β放射性,占比均为47%;其次是消毒剂指标和消毒副产物指标(臭氧、总氯、ClO_(2)、甲醛、溴酸盐、亚氯酸盐和氯酸盐),占比为6%~22%,不具备检测能力的原因包括无设备、无标准品、无试剂和无检测人员;非常规指标中,除了氨氮(1%)外的63项指标不具备检测能力的机构占比均≥19%,其中贾第鞭毛虫和隐孢子虫不具备检测能力的机构占比最高(65%),主要原因为无设备(88%),其次为无检测人员(42%~43%)、无试剂(40%)和无标准品(38%);其余61项指标不能检测的原因为无设备、无标准品、无试剂和无检测人员(占比分别为60%~76%、45%~62%、42%~53%、51%~67%)。县级CDC常规指标中,放射性指标检测能力最弱(总α放射性和总β放射性,占比均为85%),其次是消毒剂指标和消毒副产物指标(臭氧、总氯、ClO_(2)、甲醛、溴酸盐、氯酸盐、亚氯酸盐、四氯化碳和三氯甲烷),不具备检测能力的主要原因以无设备(83%~94%)和无检测人员(53%~76%)为主。结论省、市、县CDC常规指标检测能力不足主要体现在放射性指标(省、市、县CDC),消毒剂指标(臭氧、总氯、ClO_(2))、消毒副产物指标(甲醛、溴酸盐、亚氯酸盐、氯酸盐)(市、县CDC),以及四氯化碳、三氯甲烷(县CDC);非常规指标中氨氮检测能力较好(省、市CDC),检测能力不足主要体现在贾第鞭毛虫和隐孢子虫(省、市CDC),及其他指标(市CDC)。检测能力不足的主要原因是设备配置不到位,今后应该重点从增配设备着手,增强水质检测能力。展开更多
The weights of the drought risk index (DRI), which linearly combines the reliability, resiliency, and vulnerability, are difficult to obtain due to complexities in water security during drought periods. Therefore, d...The weights of the drought risk index (DRI), which linearly combines the reliability, resiliency, and vulnerability, are difficult to obtain due to complexities in water security during drought periods. Therefore, drought entropy was used to determine the weights of the three critical indices. Conventional simulation results regarding the risk load of water security during drought periods were often regarded as precise. However, neither the simulation process nor the DRI gives any consideration to uncertainties in drought events. Therefore, the Dempster-Shafer (D-S) evidence theory and the evidential reasoning algorithm were introduced, and the DRI values were calculated with consideration of uncertainties of the three indices. The drought entropy and evidential reasoning algorithm were used in a case study of the Haihe River Basin to assess water security risks during drought periods. The results of the new DRI values in two scenarios were compared and analyzed. It is shown that the values of the DRI in the D-S evidence algorithm increase slightly from the original results of Zhang et al. (2005), and the results of risk assessment of water security during drought periods are reasonable according to the situation in the study area. This study can serve as a reference for further practical application and planning in the Haihe River Basin, and other relevant or similar studies.展开更多
文摘The subsided water areas with different times of subsidence are chosen to monitor the physicochemical indexes and heavy metal elements. The results indicate that subsided water areas are polluted in different degree. Some physicochemical indexes of subsided water areas are increased with the development of the subsidence and are changed with the changing of the season. The concentration of As, Cd, Cu, Pb, Se, Zn of subsided water areas is less than national fishery, and surface water quality standards of China , except Hg. And the quality of subsided water hasn't been polluted by heavy metal seriously. Analyzing and appraising the quality of the subsided water can give a reasonable data as basis in using the subsided water resource.
基金Supported by China National Science and Technology Major Project(2016ZX05016-006)
文摘Through reviewing the generation process and essential characteristics of waterflooding curves, the essence and characteristics of Zhang Jinqing waterflooding curve and Yu Qitai waterflooding curve recommended in Chinese Petroleum Industry Standard 'Calculation methods for Recoverable Oil Reserves(SY/T5367—1998)' were discussed, and some technical issues related to the curves were examined in-depth. We found that:(1) All the waterflooding curves are based on empirical formulas derived from oilfield production experience and statistics methods, and can characterize oil displacement features by water quite well.(2) A new waterflooding curve can be derived by combining waterflooding parameters and using different mathematical calculations as long as the parameter combinations and mathematical operation meet a linear relationship, so proposing new waterflooding curves by changing the combination mode has no practical significance anymore.(3) The upwarp of waterflooding curve in the extremely high water cut stage is because the mobility ratio curve has an inflection point with the rapid rise of water cut after reaching a certain value, and the later rapid rise of mobility ratio changes the original two-phase flow dynamics.(4) After entering into water cut stage, all the waterflooding curves with linear relationship can be used to make prediction, even curves with inflection points, as long as they have a straight section above the inflection point.(5) Actual data of waterflooding oilfields has proved that Type A, Zhang Jinqing and Yu Qitai waterflooding curves all can predict accurately oil recoverable reserves in extremely high water cut stage and can be promoted.
文摘目的了解2022年省、市、县疾控机构(Center for Disease Control and Prevention,CDC)对《生活饮用水卫生标准》(GB 5749-2006)中规定的106项指标的检测能力,分析省、市、县各指标检测能力不足的主要原因。方法收集2022年度全国各级CDC水质检测能力数据,对省级、地市级CDC的42项常规指标、64项非常规指标和对县级CDC的42项常规指标不具备检测能力的机构占比及不能检测的原因占比进行分析。结果省级CDC检测能力不足主要体现在总α放射性、总β放射性(4个省级,占比14%)和贾第鞭毛虫、隐孢子虫(6个省级,21%),主要原因均为设备配置不到位(100%),其次是无检测人员(50%~75%)。地市级CDC常规指标检测能力不足主要体现在总α放射性和总β放射性,占比均为47%;其次是消毒剂指标和消毒副产物指标(臭氧、总氯、ClO_(2)、甲醛、溴酸盐、亚氯酸盐和氯酸盐),占比为6%~22%,不具备检测能力的原因包括无设备、无标准品、无试剂和无检测人员;非常规指标中,除了氨氮(1%)外的63项指标不具备检测能力的机构占比均≥19%,其中贾第鞭毛虫和隐孢子虫不具备检测能力的机构占比最高(65%),主要原因为无设备(88%),其次为无检测人员(42%~43%)、无试剂(40%)和无标准品(38%);其余61项指标不能检测的原因为无设备、无标准品、无试剂和无检测人员(占比分别为60%~76%、45%~62%、42%~53%、51%~67%)。县级CDC常规指标中,放射性指标检测能力最弱(总α放射性和总β放射性,占比均为85%),其次是消毒剂指标和消毒副产物指标(臭氧、总氯、ClO_(2)、甲醛、溴酸盐、氯酸盐、亚氯酸盐、四氯化碳和三氯甲烷),不具备检测能力的主要原因以无设备(83%~94%)和无检测人员(53%~76%)为主。结论省、市、县CDC常规指标检测能力不足主要体现在放射性指标(省、市、县CDC),消毒剂指标(臭氧、总氯、ClO_(2))、消毒副产物指标(甲醛、溴酸盐、亚氯酸盐、氯酸盐)(市、县CDC),以及四氯化碳、三氯甲烷(县CDC);非常规指标中氨氮检测能力较好(省、市CDC),检测能力不足主要体现在贾第鞭毛虫和隐孢子虫(省、市CDC),及其他指标(市CDC)。检测能力不足的主要原因是设备配置不到位,今后应该重点从增配设备着手,增强水质检测能力。
基金supported by the National Natural Science Foundation of China(Grants No.51190094,50909073,and 51179130)the Hubei Province Natural Science Foundation(Grant No.2010CDB08401)
文摘The weights of the drought risk index (DRI), which linearly combines the reliability, resiliency, and vulnerability, are difficult to obtain due to complexities in water security during drought periods. Therefore, drought entropy was used to determine the weights of the three critical indices. Conventional simulation results regarding the risk load of water security during drought periods were often regarded as precise. However, neither the simulation process nor the DRI gives any consideration to uncertainties in drought events. Therefore, the Dempster-Shafer (D-S) evidence theory and the evidential reasoning algorithm were introduced, and the DRI values were calculated with consideration of uncertainties of the three indices. The drought entropy and evidential reasoning algorithm were used in a case study of the Haihe River Basin to assess water security risks during drought periods. The results of the new DRI values in two scenarios were compared and analyzed. It is shown that the values of the DRI in the D-S evidence algorithm increase slightly from the original results of Zhang et al. (2005), and the results of risk assessment of water security during drought periods are reasonable according to the situation in the study area. This study can serve as a reference for further practical application and planning in the Haihe River Basin, and other relevant or similar studies.